I've been cleaning carbs for more than 40 years. I've worked at an outboard shop & a couple of motorcycle shops. This is the best description of what to do, how good it needs to be done & why you need to do it, that I have ever come across. You did a great job. Two thumbs up. I watched this video because I needed to find the idle mix screw on a Merc carb & it was a dead ringer for the one carb that you showed. I saw the location of the screw on yours. I didn't see the plug on mine at first because it was behind the choke linkage. You taught an old dog a new detail. Thank You
Hey, I just boat my first boat and I’m having some issues that I think is the carburetor. Do you think I can give you a call or text and you can help me out? Every where around me they want $450 to clean 1 carburetor… which is ridiculous.
There is absolutely nothing but great information in this video but just a point from my 9.9 use and quick but permenent fix. My best friend was a carburetor man for 45 years the absolute best. He couldn’t clean repair mine after tearing apart couple times. I bought a new on not that expensive.Didn’t work I new the motor had plenty hours but I new motor was perfectly good. Then he noticed in the picture same carb upper left hand ther is a round circle with a plug in it. Popped it out there was the air fuel mixture screw. Epa requirement cap for new factory setting not to be touched. Wear tear varnish whatever just a little turn giving motor more air and it ran like new. That motor keep running like new for three more years putting 400 hours a year on it. Bought a newer boat and gave that motor to a friend. It’s still going like new. Hard starting rough idling that’s your baby. I live at the beach and it’s worked everytime I showed that cap trick to others that come and go from resort.
I am sitting on a yatch in a remote part of Australia, population density 1 person per 100 square kilometers. 😀300 nautical miles, 2 weeks from the nearest Yamaha outboard service centre. My outboard will not idle properly and cuts out when turning the accelerator. This is a brilliant step by step explanation of what could be wrong with the carburetor and how to diagnose it. Thanks Canada Wild
Ok, I must comment. This is hands down the best outboard carburetor instructional video on UA-cam. I rarely ever subscribe to the content creators but I certainly said I must subscribe to this channel! I've repaired my Yamaha four-stroke carburetors numerous times, but I've had to reclean them. This video gave me a much better understanding of the carburetors and how to go about troubleshooting. I really appreciate you taking the time and wish we had such a good mechanic down here in San Diego.
The best lesson on small boat carburettors I have ever seen. I have 4 small engines that get little use and long periods of storage. Yesterday I partially stripped down a Yamaha 4 carb, hoping cleaning a few bits would help. It did start but ran very roughly. Today I've done it again understanding what I was actually doing... ( Yes it helps) Now it running beautifully.... Thanks for a great lesson.
Guitar strings would work great, different sizes too. Just be careful to not scratch the passageway in the jet, it can disrupt flow. This disruption is much more noticeable with newer engines that are more concerned about emissions.
I have been tearing my hair out getting my 6 hp Tohatsu to run reliably and your video has given me the confidence to tackle a thorough carby check. Excellent video ,Thank you!
Great educational video on the 4 carburetor circuits and how to race trace in the casting. Love the use of aerosol lubricant to check passageways. Also great explanation of the needle and seat and confirmation of when the needle and seat is open and when its closed. Thanks so much for sharing!
The corrosion is the part that tells me. You are 100% correct. I would advise the owner not because of the varnish Gunk build up cuz that could be cleaned it's more of a metallurgy seating issue. If you can get one and afford it that definitely qualifies is investing in the new body at least not to mention gasket kit that's why, don't leave fuel in your engine. Outboards like to be run honestly all the damn time at least twice a week the buildup one stress on impellers when you break in a motor have a system where I protect the water jackets with a thin layer of lubricant it is for impellers as well run fresh water through them once in a while also a very good tip. But this guy is good he knows his stuff
I would say that this was really good! One of the best I have seen. Helped me today with my Hide(Yamaha) and will help me with my Tohatsu when I will fix that one. Thanks
An excellent presentation. I learned a lot. I just bought a boat that wasn't prepared properly for winter and having issues getting it to start. It will run with a light spray of starting fluid, but not beyond that. It's looking like I will have a carb teardown in my near future.
I do not like starting fluid. If the motor doesn't start, something is wrong. Diagnose what is wrong and fix it, then the motor will start. Starting fluid will not diagnose or fix what is wrong. A engine needs spark, fuel and compression to start, it also needs to correct amount of those things at the correct time. breaking it down into those six parameters simplifies the diagnostic procedure.
Again, thank to share your expertice. Yoy are a geniuos. And mechanical Enginieers, please, as you see, the carburator has 100% chance of failure !! You must know other ways to restrict flow other than tiny holes that can be blocked any time, any where.
Thanks for taking the time to share your knowledge. Having seen this Im going right now to check the idle problem I have with my almost brand new 20 hp honda engine. Its idle circuit or probably float problem. /Thanks in advance! Regards, Johann from uruguay!
Great video. Very informative. I had to clean my Yamaha 25 carb yesterday. It was just like the one you showed from your junk stash. I wish I had watched your video first as it would have made things much easier and I would have understood what was going on more. I did manage to get it apart and back together and it seems to run fine now.
Nice job, my new 15 yamaha 4 stroke new yamaha tank, and hose not broken in yet. After the winter had no high speed. Open it up clean gas and high speed jet had small brass fleck in it from factory. That automatic electric choke i dont trust. I have yamaha 3 and 5 hp, 2 stroke best running motors i have ever seen. This 15 yamaha 4 stroke worst motor i have owned. My Suzuki 25 4 stroke 3 cyl 3 carbs nice motor!
Thanks for sharing your wisdom. I learned alot and managed to pull apart a triple carby, clean and replace it thanks to you. I have the mercury carby shown in the accelerator circuit. My question is, if fuel is leaking from the bellows on the accelerator pump, would this cause bogging? The jet it feeds into is still working and squirting fuel yet the engine bogs at mid throttle.
Best video I've found. And like you said, so simple. Thanks. Hopefully i get it running now. Especially since it was running before i decided to take it apart. But it wasn't running happily over half throttle.
Thank you. If it's a carb problem, over half throttle is running on your main jet, so be looking for a varnish buildup on the jet, or maybe low float level. A restriction or air leak in the fuel supply can also cause problems over half throttle.
@@CanadaWideMarine thanks. For the tips. Carbs clean. Was to begin with. Everything checked out. Still wont start. Spritz carb clean in there just a shorty hefty "i wanna start." Nnnn nothin. Guess ill be figuring everything out about small outboards instead of enjoying the river.
Very informative video. I have a yamaha 8hp and the idle 'hunts' like it's not getting enough fuel. This will help me a lot in doing a tear down and clean. Thanks!
Can you make the main jet a little larger (maybe make the percolation tube air holes a little larger as well) and get more performance (hp)? Maybe you have to bore the air chamber out some too??? No that probably wouldn’t work, the throttle plate would need to be larger after doing that, right? Is there a pretty simple “trick” to get a little more high end performance on a 15 yammy? Thank you for the information just past 22:05, I definitely learned something there, really the whole vlog 👍🏻👍🏻👍🏻 Had to rewind a bunch of times. You do a really good job of getting small parts in the middle of the screen and not moving around much, it helps when I zoom in to see it. Also learned it’s pretty important to have an external fuel filter/water separator to keep the dog’s hair and water out of the fuel system. 30:20 thanks for showing how to view the idle transfer holes ❤❤🎉🎉🎉
If I was in 🇨🇦 I know exactly who I would take my outboard to for repair. 150 👍🏻 I also know where to get parts too. Liked and a repeat subscriber, my other UA-cam account got lost (maybe that’s why guys lose subscribers sometimes, UA-cam figures out the accounts aren’t being used anymore?) when I couldn’t remember the password to the email account it was linked to 😔
Hi, I have the same carbs on my F75 yamaha. I pulled the carbs off and cleaned them up, reassembled and reinstalled but still popping and backfiring at idle and worse with increased rpm. The only thing I didn't remove on the card was the idle jet on the side because the needle has a brass cap on the outside...should I remove this cap and remove needle screw or not. Great video, sure would b great to chat to you. Thanks
Great explanation. Thank you. How important are those little inline green filters that are sitting in carburator inlets for gas? I have water separator and little net filter in engine. Just did carb service on my f90tlrc.
Turns out my accelerator was sticking open. Don’t know if that was the problem?? But it started. Now I have to figure out why it’s sticking or run it at idle only for now. The little spring at the carb maybe, or the plate has salt water buildup been the throttle plate and acceleration plate? If I can’t fix it, I can manually operate it, but that can become dangerous and subject the engine to more moisture since the cover has to be off and you’d have to turn around to slow the engine down, just want it right. She runs like a champ though, seems to be hitting the limiter now, it never did that before?? I’m at anchor so it’s my only way to shore, been oos for 4 days.
You are correct. I would say more than 90% of the time probably 95.99 unless it's totally obvious it's always a fuel issue if you have spark you have compression it's easy to test for that do you feel resistance when you pull when you pull the boot off the plug small flathead screwdriver inside the boot gently fuel for a shock of electricity. I know that's old fashioned but it works let you know that the kill switch is not the culprit the Magneto is not the culprit could be the actual plug though but I digress I recommend depending on if the motor had not been running a long time especially the fuels left in the system it will turn to Varnish clogging the Jets. Sometimes you can get away with a can of carb cleaner but that's not the right way to do it. Drain the carburetor Pump Fuel through the system trim the motor all the way up after putting in screw back in carburetor Bowl need it trimmed full up Prime system with fuel start motor I know it's in the air I know the angle don't worry your impellers will get water soon enough chances are if it's that they're cracked anyways it won't overheat in a couple minutes but it will allow motor to run. Just thought I'd pass that on to you oh yes if you do have a separator make sure the motor is getting fuel clean out the Racor if you have. But the love of God just don't start turning screws and then call someone like me to come fix it although that's easy too turn back to factory specs all the way tight count rotations you will get your air fuel mixture correct but their Motors it could be a lot of things the trim up tip was the best key I could give you but this is meant mainly on bigger motors with push start
Thank you for a great video. My engine starts well, idles fine, and runs wide open fine. The problem is when I run at midrange it will run for a bit then stall out. Or if I run wide open and then start idling down it stalls nearing idle. Any ideas? Thanks for all the help.
Hi great job, I have a F9.9 MSHC High Thrust 2004 with the electric choke solenoid on top and I wondering if this carb can work or even fit or may not work as the CDI units needs the feed back from the electric choke for timing? any help is appreciated
This was a great video. I am hoping you can solve an issue I have. I am leaking gas out of the accelerator plunge/boot. After my 2001 Mercury 25 hp 4 stroke runs and shut off, the gas will start to leak/drip out of bottom of boot. I bought a rebuild kit and replaced all pieces and gaskets and made sure the float and seed is good to go per your video. I have not stated the engine yet, but I installed the carb and moved the plunger/accelerator up and down and I am still getting gas leakage after 4 WOT pumps (by hand). I don't want to run the engine unless the air vacuum keeps the gas and air from leaking. while running. I appreciate your time. Any help would be appreciated.
Following and rechecking based on comments to another user - my carbs have been fully cleaned, and I simply have a bog when you hit it and also a miss at about 1/3rd throttle. This is a 30hp merc 4 stroke 1999. I went to add/adjust the idle mixture a little richer - but there are no adjustment needles - there is a boss in the casting which looks like it may have been in the past but no longer. Idle is perfect. You can nurse it up to higher power and it is perfect up there. Coming back down I can create a miss consistently, but only in a tight range then it goes away. I don’t have a tach easily available. It would seem to me that I need to go a size larger in the low speed jet. - any alternative suggestions?
Hi I have a 8 hp 4 stroke 2006 . Do you know the factory seting for that small jet . I took it out without checking . I will try one full turn . Nice to know. Thanks.
Will an incorrect float height create a lean running condition? I recently replaced 4 floats on a Yamaha F100. I was getting a lean sneeze around 2800-3200 rpm. Inspected the plugs and saw #1, #2 and #4 running lean. I’m thinking the float height will need to be looked at again. Idling great, and high speed boat runs great. I was thinking of enriching the idle mixture screw to compensate, but I think I’ll tear it down again and make sure floats are set correctly, as they should be.
Thank you for awesome video, I have 2001 Yamaha T50TLRZ I’ve have clean the carbs, where do I start setting the air/ fuel mixer at some forms Start at 2-1/4 on carbs 1,2 and3, 4 carb at 2 1/2 turns out? Do you know where it should be. Thank you
Thank you very much for such detailed explanation of how all these works. I have 2004 F90TLRC, new to me. Low hours and clean carbs. It idles at between 9000-1000 when warm. Spark plugs are dry and more on white color(all 4 plugs similar color), indicating lean mixture. I am trying to avoid possible overheating and want to run engine in optimal way. Dont have starting problem or power at high RPM/speed. Engine runs and responds fine. I put about 20 hours on it with no problem. Questions: 1.Do these engines tend to run a little lean(emission regulations) and I do not have to worry about plugs being not tan in color? 2.Do I want to play with butterfly screw on bracket to bring RPM down to 800ish? May be play with idle muxture screws? But there are 4 of those and I do not want to mess existing setting. Thank you very much in advance. Any thoughts or suggestions will be greatly appreciated.
Hello Ilia. If you are not experiencing lack of power or driveability issues, (surging, etc) at WOT fully loaded then I would not be concerned about very clean spark plugs. I would definitely adjust the idle speed down. I don't have the Yamaha recommended idle speed handy, but 900 to 1000 rpm sounds a little fast. The bast way to adjust your idle is with a carb sync vacuum gauge setup. A vacuum gauge connected to each intake manifold runner so that all four carbs are balanced.
@@CanadaWideMarine thank you very much Sir for such a detailed answer. It is exactly what I wanted to know. I was thinking to invest in carb cync tool and you just made it easy for me. Yamaha says 850 is recommended RPM. So I will play with that. Will report here as well. I also downloaded factory manual, but it does not describe too much about working on engine. And I am a subscriber now.
Thank you great informative video. My question is at what RPM does the idle function stop and you go on the main circut. I have a 20 HP Honda that idles fine and runs great at mid range and WOT but trolling at 1000 to 1200 RPM the engine stalls but restarts instantly. Sometimes this happens every minute and is frustrating. I have an inline fuel filter and that was clean. It gets a great squirt of gas from squeezing the inline fuel pump. The plugs look great. Any direction would help thank you
The idle circuit operates in 2 stages. The first stage, is complete idle, with the throttle fully closed. The second stage is called the transfer stage, it operates through about the first 5 degrees of throttle opening. In the transfer stage you are getting a little extra air coming past the throttle blades, but not enough to start the main circuit flowing. That little bit of extra air draws fuel out of the transfer holes that you can see just behind the main idle hole behind the throttle blade. This extra fuel comes from the idle circuit. So at trolling speeds, 1000 to 1200 rpm you are most likely still on your transfer stage of the idle circuit. To remedy this situation I generally richen up the idle mixture screw a little, about a quarter turn counter clockwise usually takes care of it. You may have to remove the cap over the idle screw. Some older Hondas have an idle screw with a limiter stop on it which can be a problem. open it up as far as it will go.
Full throttle fluctuations in engine RPM are often caused by a lean mixture, slightly restricted main jet, vacuum leaks low float level, restricted fuel filter or fuel supply, air leaks into fuel supply. Other causes cold be bad spark plugs, weak ignition system, Poor quality electrical system, check grounds in particular, but also all battery connections and battery switch etc. Even a corroded battery switch or kill switch. In summary, there can be many causes and it is impossible for me to say what is wrong without diagnosing the issue myself.
Fuel comes out of the overflow because there is too much in the float bowl. Many small outboard carbs have a fuel inlet in the bottom of the float bowl, with a passage through the float bowl into the main body of the carb where it the goes to the needle and seat. That passageway is sealed between the main body and the bowl with the float bowl gasket, (which is actually a formed rubber o ring). If the float bowl gasket seal is not sealing correctly you will get too much fuel in your float bowl through the leak in the seal into the float bowl. Other causes of too much fuel in the float bowl could be incorrect float level, sticking float, (not moving freely), or a sunk float usually caused by the float filling up with gas from a leak into the float. Give the float a shake and you will hear liquid in it if this is the case.
Hi there my Yamaha 2007 T 9.9 it was running only with the chalk little bit out. I can drive it that way, but as soon as I put the chalk in it stops I came up to your video which is one of the best I watch lately thank you for your good work I took my carburetter apart the way you showed when I came to the idle jet, somebody’s been there before me and broke that slot for the screwdriver. I couldn’t take it out so I decided I’m going to use a small easy out to pull it out. I was doing good but soon got hart to turn it but all of a sudden got tight and I didn’t succeed. Is it anyway that this carburetter can be used by drilling and doing something else so I don’t have to buy a new one. Please advise what is my options? Thank you.
you could try heat. get the carb body really hot before trying the easy out again. The heat expands the aluminum body and may loosen the jet in the body.
Hi. Thank you so much for the create video explanation how the carb works. I am actually very interested in the mecury carb plunger (video 19.12 min) could a wrong adjustment of it also make the engine run rich? Ive adjusted the airflow and got the engine run in idle very nice but sparks are dry black. Carb is cleaned and Checked the needle like you showed upside down blowed and it seals of nicely no leaking. I cant get my head around why the sparks are black every time after I tripple checked it and adjusted it. Greetings from Holland. Davis.
If you are getting black spark plugs it is usually a sign that the engine is getting too much fuel. Now, I need to assume you are running the correct plugs, and new plugs. Engine oil has been changed recently. (old oil will foul spark plugs), Compression is good. Also assuming the main jet is the original. That leaves float height. If the float level is too high, even just slightly, it will allow he engine to get too much fuel. The accelerator pump adjustment will not affect mixture, it only operates when the throttle is moved.
Thank you for the information, I have 40hp 4 stroke and I have had the engine not speeding up no matter how much gas I put on so I thought it's the carburetor and got it off cleaned it and replaced it back but it's still the same , I'm thinking to buy new jets Any site recommendations ? Maybe you think I have a different problem? Thank you in advance
My advice would be to have your motor diagnosed by a reputable marine mechanic before spending money replacing a carb that may or may not be the problem. It should only take an hour or two for a good mechanic to thoroughly diagnose your problem and advise on a course of action to repair. Without seeing the motor in person there is no way I can possibly identify what might be wrong with it.
Great video! I do have a question about my Yamaha 40 Hp 4 stroke, I have a diaphragm assembly and there is a spring on there that wasn’t engaged I think I put it on right but now I need to adjust it so it works in accordance to the throttle
I'm not sure which spring and diaphragm you are referring to? You are welcome to email some photos to support@canadawidemarine.com and I might be able to help you out.
I have learned quite a bit by watching your work. I have a 1999 Evinrude 6RL4EEM 99, 6 hp, 4 stroke. The carb has an accelerator pump on the bottom, which water flows through. Have you ever seen a carb like that? There are no parts available for the accelerator pump, but the carb kit is available. The engine bogs upon acceleration but otherwise starts and runs good. I haven't rebuilt the carb, but took the carb off the motor and took the float bowl off and it's very clean inside. Is there any sense in rebuilding the carb since I can't fix the accelerator pump? Also, the motor uses a very rare fuel pump. No rebuild kit available and a replacement fuel pump is $166.00. It's a good little motor used on a sailboat. When docking, sometimes you need a little rev and that's when the motor bogs and sometimes dies. Not sure what to do. Thanks
This is the problem we are seeing a lot of these days, parts no longer available for older motors. Is your accelerator pump diaphragm leaking fuel? if it is then you have a fire risk of course, if it isn't then we need to look into why the motor is not getting enough fuel on quick acceleration. a dirty or sticky check valve on the accelerator pump is a good starting point. an air leak on the inlet side of the accelerator pump is another, (when the pump is re-filling it can suck air instead of fuel sometimes). another thing that might help is to richen up the idle mixture a little bit, or raise the float level ever so slightly. I assume a new diaphragm does not come in the rebuild kit? Tough choices with an older motor, we have had to scrap many motor for lack of parts available to repair them. And I think the problem is only going to get worse in the future.
@@CanadaWideMarine Thanks for the quick reply. I don't see any fuel leakage from the accelerator pump. I do see 2 little check balls/valves inside and they are both clean and free. The diaphragm seems pliable. The carb kit does not contain accelerator pump parts. I can see someone has been inside the carb because they stripped the drain plug in the bottom of the plastic float bowl and also one other screw by the accelerator pump. I will fix these issues, spray some carb cleaner and test again. I will try your suggestion on the idle mixture. Do you know if my fuel pump 0445078, might be compatible with any modern pumps? I don't want to mess with it at the moment since I can't get parts and the price of a new one is ridiculous. Thanks again
@@CanadaWideMarine Ok, thanks for your time. FYI, upon further inspection I now see the little diaphragm for the accelerator pump is split. Since the part is no longer available, I made a tiny gasket that fits under the entire diaphragm out of inner tube rubber as a test and I can get it to pump water. So I ordered a sheet of thin nitrile to make a permanent fuel proof gasket. Haven't tested it running yet, but I think I have a chance. "It's amazing what you can do when you have to do it"
Hi, I am disassembling the carb assy. on my 2001 Yamaha 50 HP 4 stroke. Can you tell me what the trick is to releasing the link rod bridging the 4 carbs and also the link rod from the accelerator pump at the carb end? Both parts seem to be snapped into place, no cotter pins involved. Is it a matter of pulling at the joint to release? I don't want to damage anything> Thanks again for all your great videos and explanations. Jim Murphy
Hi Jim, Yes, you got it right, the linkage snaps off. I usually use a pair of needle nose pliers to get underneath the linkage and pry gently against the arm so I am not bending the arm as I pull the linkage off. Thanks for watching.
Thank you very much for this great explanation of how carburettors works. I have a Yamaha 2002 F60TLRA from new with 1800 engine hours, it is a trailer boat used in freshwater for walleye and lake trout trolling. The engine is hard to start when cold or first time that day, it normally stalls a least 10 times before it runs fine . I suspect it is caused by a vacuum leak in the prime start system, (as you describe in the video) i also idles a little bit rough around 700 to 900 rpm. i plan to rebuild the carburettors with 4 new carb kits. When the engine was new i had a lot more power (same boat not much added weight) i know that it is quite common that engines lose some power with time, but i am wondering if it is possible to gain some power back? Spark plugs are dry and more on white colour (all 4 plugs similar colour), indicating lean mixture. I am wondering if new larger main jets would yield more power in the mid range 3500 to 4500 rpm?. . Thank you very much in advance. Any thoughts or suggestions will be greatly appreciated.
On some carbs they are indeed separate. It doesn't really matter because at low speed when fuel is metered through the pilot jet, or idle jet, the main circuit is not functioning, so the only fuel going through the main jet is for the pilot jet, (if they are incorporated together). At high speed there is no fuel going through the pilot jet so it does not take away from the main jet metering. Hope that helps
Thanks for that good video and the explanations. One question: to follow the pipes, you put what in? Which spray is this? If I understood correctly, also WD40 works but do I than have to clean the carb again because of the oil? Or does the oil not harm the working of the carb? Thx a lot for your help.
WD40 would work just fine. In fact WD40 is a bit of a solvent and will help clean the internal passages. Blow it all out and off before final assembly. a little residue from the oil will not harm anything.
Can I remove the welch plug covering my idle mix screw? It doesn't need to be replaced after either? Great video, I learned a few helpful things, been tearing carbs apart for 30yrs as an amateur, lol.
Hey buddy, yes you can, but be VERY CAREFUL. You need to drill a hole and pop it out. Its a little brass plug. Stop drilling when you hit another piece of metal. That would be your mix screw
Orlando beat me to it, great answer. Yes, you absolutely can. I generally use a 1/8" drill bit to put a small hole in the plug, then tap a #8 self tapping screw into it. being careful to not screw it in too far and damage the mixture screw in behind the plug. Basically don't force the screw, just in enough to get a bite. Grab the screw with some pliers or vice grips to pull the plug out. And no, you do not need to replace the plug after. The plug is there so people cannot richen the idle up to meet emissions requirements.
Thanks for the replies. It was round 2 for carb clean, 1st time didn't work, but it turned out to be those pin holes in the idle jet, reamed out with my guitars high e string and im back on the water! Spring salmon are here and motors running perfect. The video saved me! But I might still pop that welsh plug, I dont really like it🙂
Very good video. Question I have a 2011 90 Hp Mercury 4 stroke. My will take off from idle and get on plane and run for about 200 yards then bogs down. Do you think that the float is sticking and not allowing fuel to enter the bowl or something else?
There are many things that can cause those symptoms. I would start with checking the whole fuel supply system. Looking for restrictions or leaks that can allow air to be sucked into the fuel line
is there a screen under the needle seat ? having trouble blowing air through to the bowl even without the needle in . having a hard cold start but runs well after i get it going . 03 8 horse 4 stroke yamaha with nikki carb
There is no filter screen under the seat, but you could have something lodged in there before the seat. Have you tried blowing backwards with air pressure from the needle side? ON an older motor like that with hard starting cold, assuming plugs, compression and all the basics are in good shape I would start looking at the carb to manifold seals, they get hard and flatten out so they leak a little air when cold.
I've cleaned my carbs out good and changed fuel lines. My issue is when I gas it and let off it dies. If I go slow she'll power up. It's when I come down from throttle it cuts.
There are many possible causes for that type of issue. I would recommend a proper diagnostic by a marine mechanic. The diagnosis is almost always cheaper than just replacing random parts until the problem is solved. I could suggest a handful of things to check, only to find the problem is something I didn't mention and that doesn't help anyone.
Sounds to me like an adjustment issue on your carburetor setting. They have air fuel mixture screws it's not receiving the proper amount of air or it's being bogged down by too much gas that is most definitely your problem and if it's not that it could be a vacuum leak or the actual teeth that hold down the float Bowl regulator they do tend to bend upward and allow too much fuel sometimes just the side note took me a while to find that one time
I am assuming you mean the boot on the accelerator pump. This is caused by a cracked diaphragm, very common. As you disassemble it, keep track of the location of the springs, and it is pretty easy to replace. The diaphragm does not come in the carb rebuid kit, you must buy it seperate.
Hi Greetings from Australia Got a 2016 suzuki 8hp 4 stroke outboard How many carb adjustments for this motor pls ? How many turns out for base speed for full throttle top speed performance pls ? Thanks Glen Australia
Hi Glen, I spent almost 20 years in Australia, it treated me well. There are no adjustment screws on your carb that will affect full throttle performance. Full throttle mixture is adjusted with the main jet. Now, if you are experiencing a lack of performance, a running issue at full throttle, many things can cause that. Just with the carb poor full throttle performance can be caused by a restricted main jet, incorrect float height and drop, vacuum leaks. Other causes of poor performance at full throttle can be bad spark plugs, weak ignition system, weak electrical system etc.
Good day, If you can help. I have second carburetors that you show, Mercury, Tohatsu. ITs overflow on idle. I clean all 20x times, needle is sealing, but still on idle it overflow after 10 seconds of working. Thank you upfront.
If it has the fuel inlet in the bottom of the float bowl you likely have a leaking float bowl gasket. It leaks fuel from the inlet passage into the float bowl. Hope that helps. Thanks for watching.
@@CanadaWideMarine I want to thank you in my and my dad name. You help us a lot. You explain how FLOAT should stay. Yesterday according to knowledge that you gave us I check float level with brand new spare parts and saw that is wrong. I put back old parts and now all things are fine. Thank you 100 more times that you help us.
I recently cleaned my Merc. 15hp 4 stroke carburetor. I’ve no leaks or purging. Seems to run as should. However, the primer bulb on the motor itself, not the fuel line primer doesn’t get firm. Any idea what the cause could be?
I have nothing Suzuki specific, but watch for an upcoming video on general adjustments of idle mixture and speed. Float level is covered in this video. Thanks for watchng.
![Yamaha 4 Stroke Outboard Engine Carb Rebuild Series [2] Carb Disassembly and Cleaning](http://i.ytimg.com/vi/nj0Jr0kdLAw/mqdefault.jpg)
I've been cleaning carbs for more than 40 years. I've worked at an outboard shop & a couple of motorcycle shops. This is the best description of what to do, how good it needs to be done & why you need to do it, that I have ever come across. You did a great job. Two thumbs up. I watched this video because I needed to find the idle mix screw on a Merc carb & it was a dead ringer for the one carb that you showed. I saw the location of the screw on yours. I didn't see the plug on mine at first because it was behind the choke linkage. You taught an old dog a new detail. Thank You
Nothing better than a compliment from our peers in the industry. Thank you.
Ditto, was looking for my mix screw on my Merc this video helped a ton.
Hey, I just boat my first boat and I’m having some issues that I think is the carburetor. Do you think I can give you a call or text and you can help me out? Every where around me they want $450 to clean 1 carburetor… which is ridiculous.
There is absolutely nothing but great information in this video but just a point from my 9.9 use and quick but permenent fix. My best friend was a carburetor man for 45 years the absolute best. He couldn’t clean repair mine after tearing apart couple times. I bought a new on not that expensive.Didn’t work I new the motor had plenty hours but I new motor was perfectly good. Then he noticed in the picture same carb upper left hand ther is a round circle with a plug in it. Popped it out there was the air fuel mixture screw. Epa requirement cap for new factory setting not to be touched. Wear tear varnish whatever just a little turn giving motor more air and it ran like new. That motor keep running like new for three more years putting 400 hours a year on it. Bought a newer boat and gave that motor to a friend. It’s still going like new. Hard starting rough idling that’s your baby. I live at the beach and it’s worked everytime I showed that cap trick to others that come and go from resort.
I am sitting on a yatch in a remote part of Australia, population density 1 person per 100 square kilometers. 😀300 nautical miles, 2 weeks from the nearest Yamaha outboard service centre. My outboard will not idle properly and cuts out when turning the accelerator. This is a brilliant step by step explanation of what could be wrong with the carburetor and how to diagnose it. Thanks Canada Wild
Wow! The best and most useful carb description I’ve ever seen. A gem of a video.
Ok, I must comment. This is hands down the best outboard carburetor instructional video on UA-cam. I rarely ever subscribe to the content creators but I certainly said I must subscribe to this channel! I've repaired my Yamaha four-stroke carburetors numerous times, but I've had to reclean them. This video gave me a much better understanding of the carburetors and how to go about troubleshooting. I really appreciate you taking the time and wish we had such a good mechanic down here in San Diego.
Wow, thanks!
The best lesson on small boat carburettors I have ever seen. I have 4 small engines that get little use and long periods of storage. Yesterday I partially stripped down a Yamaha 4 carb, hoping cleaning a few bits would help. It did start but ran very roughly. Today I've done it again understanding what I was actually doing... ( Yes it helps) Now it running beautifully.... Thanks for a great lesson.
I save all my old guitar strings for cleaning carbs they work wonderful. Thanks for your hard work and wisdom sir.
Guitar strings would work great, different sizes too. Just be careful to not scratch the passageway in the jet, it can disrupt flow. This disruption is much more noticeable with newer engines that are more concerned about emissions.
This was a great video one of the best instructional videos I’ve seen of a carb rebuild. Great job.
I have been tearing my hair out getting my 6 hp Tohatsu to run reliably and your video has given me the confidence to tackle a thorough carby check. Excellent video ,Thank you!
Thank you for this! Helped me fix my grandparents’ mercury
Really good instructions and explanations of how everything works and the causes and consequences of various faults, etc.
Great educational video on the 4 carburetor circuits and how to race trace in the casting. Love the use of aerosol lubricant to check passageways. Also great explanation of the needle and seat and confirmation of when the needle and seat is open and when its closed. Thanks so much for sharing!
Thanks for the great review!
Is there any way that i could get ahold of u to pick ur brain
@@eliseoromero2926 fire away if i can help...
The best video on UA-cam with regard to sorting out a carburettor. Perfect. Many Thanks.
Wow, thanks!
What an absolute fantastic video on carburettor cleaning.Thank you for the great explanation.
Love it the best explanation of problems with carbs and how to correctly clean a carb the best on you tube
Best educational video I have seen on carbs
Thanks for the kind words.
Excellent video of how a carb works and how to check for plugged circuits and dirt the best i have ever viewed
Wow really great video. Unbelievably solved my problem. You saved a fisherman's boat from Turkey. :) You knowledgeable people, glad to have you. 😀🙏
Thank you. So glad I could help.
Thanks - I needed to know what problems are caused by the fuel level in the float bowl.
The corrosion is the part that tells me. You are 100% correct. I would advise the owner not because of the varnish Gunk build up cuz that could be cleaned it's more of a metallurgy seating issue. If you can get one and afford it that definitely qualifies is investing in the new body at least not to mention gasket kit that's why, don't leave fuel in your engine. Outboards like to be run honestly all the damn time at least twice a week the buildup one stress on impellers when you break in a motor have a system where I protect the water jackets with a thin layer of lubricant it is for impellers as well run fresh water through them once in a while also a very good tip. But this guy is good he knows his stuff
I would say that this was really good! One of the best I have seen. Helped me today with my Hide(Yamaha) and will help me with my Tohatsu when I will fix that one. Thanks
Thank you Jöns, very happy to hear this video helped you out.
Brilliant and informative video thank you
Thanks for doing such an informative video. I’ve cleaned lots of carbs but I feel enlightened by all your good information.
An excellent presentation. I learned a lot. I just bought a boat that wasn't prepared properly for winter and having issues getting it to start. It will run with a light spray of starting fluid, but not beyond that. It's looking like I will have a carb teardown in my near future.
I do not like starting fluid. If the motor doesn't start, something is wrong. Diagnose what is wrong and fix it, then the motor will start. Starting fluid will not diagnose or fix what is wrong.
A engine needs spark, fuel and compression to start, it also needs to correct amount of those things at the correct time. breaking it down into those six parameters simplifies the diagnostic procedure.
Again, thank to share your expertice. Yoy are a geniuos. And mechanical Enginieers, please, as you see, the carburator has 100% chance of failure !!
You must know other ways to restrict flow other than tiny holes that can be blocked any time, any where.
Thanks for taking the time to share your knowledge. Having seen this Im going right now to check the idle problem I have with my almost brand new 20 hp honda engine. Its idle circuit or probably float problem. /Thanks in advance! Regards, Johann from uruguay!
And now we know why they invented fuel injection.
Great video. Wish I watched it a month sooner.
Thank you for the extremely informative and detailed video
wow thanks so much sir great video helped me troubleshoot my 8hp yamaha outboard on my sailboat BIG THANKS
Perfect explanation. Thanks for making the video.
Great video. Very informative. I had to clean my Yamaha 25 carb yesterday. It was just like the one you showed from your junk stash. I wish I had watched your video first as it would have made things much easier and I would have understood what was going on more. I did manage to get it apart and back together and it seems to run fine now.
Glad to hear you got it running good. Thanks for watching.
now i have an idea how a carburetor work, just become your royal subscriber ：）
Welcome aboard! Thank you for watching.
Nice job, my new 15 yamaha 4 stroke new yamaha tank, and hose not broken in yet. After the winter had no high speed. Open it up clean gas and high speed jet had small brass fleck in it from factory. That automatic electric choke i dont trust. I have yamaha 3 and 5 hp, 2 stroke best running motors i have ever seen. This 15 yamaha 4 stroke worst motor i have owned. My Suzuki 25 4 stroke 3 cyl 3 carbs nice motor!
Thanks for sharing your wisdom. I learned alot and managed to pull apart a triple carby, clean and replace it thanks to you. I have the mercury carby shown in the accelerator circuit. My question is, if fuel is leaking from the bellows on the accelerator pump, would this cause bogging? The jet it feeds into is still working and squirting fuel yet the engine bogs at mid throttle.
Best video I've found. And like you said, so simple. Thanks. Hopefully i get it running now. Especially since it was running before i decided to take it apart. But it wasn't running happily over half throttle.
Thank you. If it's a carb problem, over half throttle is running on your main jet, so be looking for a varnish buildup on the jet, or maybe low float level. A restriction or air leak in the fuel supply can also cause problems over half throttle.
@@CanadaWideMarine thanks. For the tips. Carbs clean. Was to begin with. Everything checked out. Still wont start. Spritz carb clean in there just a shorty hefty "i wanna start." Nnnn nothin. Guess ill be figuring everything out about small outboards instead of enjoying the river.
Perfect explanation.Very useful.
Very informative video. I have a yamaha 8hp and the idle 'hunts' like it's not getting enough fuel. This will help me a lot in doing a tear down and clean. Thanks!
Glad it helped
Very informative video.Thanks!
Very informative and well explained, will apply your teaching to my next maintenance on my carbs, Thank you
Wonderful, thank you.
Can you make the main jet a little larger (maybe make the percolation tube air holes a little larger as well) and get more performance (hp)? Maybe you have to bore the air chamber out some too??? No that probably wouldn’t work, the throttle plate would need to be larger after doing that, right? Is there a pretty simple “trick” to get a little more high end performance on a 15 yammy? Thank you for the information just past 22:05, I definitely learned something there, really the whole vlog 👍🏻👍🏻👍🏻 Had to rewind a bunch of times. You do a really good job of getting small parts in the middle of the screen and not moving around much, it helps when I zoom in to see it. Also learned it’s pretty important to have an external fuel filter/water separator to keep the dog’s hair and water out of the fuel system. 30:20 thanks for showing how to view the idle transfer holes ❤❤🎉🎉🎉
Can a guy do something to make one of those carburetors run off a 20 # propane bottle??
this vidio is so good ive subscribed you thanks for info ..best description ive seen .
Excellent training, appreciate this.
Fantastic!
Thanks for the great explanation.
Thank you Mr Canada man!
Very good video! Have a good day!
If I was in 🇨🇦 I know exactly who I would take my outboard to for repair. 150 👍🏻 I also know where to get parts too. Liked and a repeat subscriber, my other UA-cam account got lost (maybe that’s why guys lose subscribers sometimes, UA-cam figures out the accounts aren’t being used anymore?) when I couldn’t remember the password to the email account it was linked to 😔
Hi, I have the same carbs on my F75 yamaha. I pulled the carbs off and cleaned them up, reassembled and reinstalled but still popping and backfiring at idle and worse with increased rpm. The only thing I didn't remove on the card was the idle jet on the side because the needle has a brass cap on the outside...should I remove this cap and remove needle screw or not. Great video, sure would b great to chat to you. Thanks
Great explanation. Thank you.
How important are those little inline green filters that are sitting in carburator inlets for gas?
I have water separator and little net filter in engine.
Just did carb service on my f90tlrc.
Turns out my accelerator was sticking open. Don’t know if that was the problem?? But it started. Now I have to figure out why it’s sticking or run it at idle only for now. The little spring at the carb maybe, or the plate has salt water buildup been the throttle plate and acceleration plate? If I can’t fix it, I can manually operate it, but that can become dangerous and subject the engine to more moisture since the cover has to be off and you’d have to turn around to slow the engine down, just want it right. She runs like a champ though, seems to be hitting the limiter now, it never did that before?? I’m at anchor so it’s my only way to shore, been oos for 4 days.
You are correct. I would say more than 90% of the time probably 95.99 unless it's totally obvious it's always a fuel issue if you have spark you have compression it's easy to test for that do you feel resistance when you pull when you pull the boot off the plug small flathead screwdriver inside the boot gently fuel for a shock of electricity. I know that's old fashioned but it works let you know that the kill switch is not the culprit the Magneto is not the culprit could be the actual plug though but I digress I recommend depending on if the motor had not been running a long time especially the fuels left in the system it will turn to Varnish clogging the Jets. Sometimes you can get away with a can of carb cleaner but that's not the right way to do it. Drain the carburetor Pump Fuel through the system trim the motor all the way up after putting in screw back in carburetor Bowl need it trimmed full up Prime system with fuel start motor I know it's in the air I know the angle don't worry your impellers will get water soon enough chances are if it's that they're cracked anyways it won't overheat in a couple minutes but it will allow motor to run. Just thought I'd pass that on to you oh yes if you do have a separator make sure the motor is getting fuel clean out the Racor if you have. But the love of God just don't start turning screws and then call someone like me to come fix it although that's easy too turn back to factory specs all the way tight count rotations you will get your air fuel mixture correct but their Motors it could be a lot of things the trim up tip was the best key I could give you but this is meant mainly on bigger motors with push start
Exact video I needed!
Thank you for a great video. My engine starts well, idles fine, and runs wide open fine. The problem is when I run at midrange it will run for a bit then stall out. Or if I run wide open and then start idling down it stalls nearing idle. Any ideas? Thanks for all the help.
Hi great job, I have a F9.9 MSHC High Thrust 2004 with the electric choke solenoid on top and I wondering if this carb can work or even fit or may not work as the CDI units needs the feed back from the electric choke for timing? any help is appreciated
Awesome video!
This was a great video. I am hoping you can solve an issue I have. I am leaking gas out of the accelerator plunge/boot. After my 2001 Mercury 25 hp 4 stroke runs and shut off, the gas will start to leak/drip out of bottom of boot. I bought a rebuild kit and replaced all pieces and gaskets and made sure the float and seed is good to go per your video. I have not stated the engine yet, but I installed the carb and moved the plunger/accelerator up and down and I am still getting gas leakage after 4 WOT pumps (by hand). I don't want to run the engine unless the air vacuum keeps the gas and air from leaking. while running. I appreciate your time. Any help would be appreciated.
Following and rechecking based on comments to another user - my carbs have been fully cleaned, and I simply have a bog when you hit it and also a miss at about 1/3rd throttle.
This is a 30hp merc 4 stroke 1999. I went to add/adjust the idle mixture a little richer - but there are no adjustment needles - there is a boss in the casting which looks like it may have been in the past but no longer.
Idle is perfect. You can nurse it up to higher power and it is perfect up there.
Coming back down I can create a miss consistently, but only in a tight range then it goes away.
I don’t have a tach easily available.
It would seem to me that I need to go a size larger in the low speed jet. - any alternative suggestions?
I do locking for a carburator for mercury 9.8 outboard
Does this also apply to smaller outboard motors? I have a 20hp mercury 4 stroke that won’t idle. Seems like a clogged idle jet.
Great video explained very well and clear
Thanks for the positive feedback!
Non ethanol fuel no longer available here on southern Vancouver Island ! CHEERS from Here1
Hi I have a 8 hp 4 stroke 2006 . Do you know the factory seting for that small jet . I took it out without checking . I will try one full turn . Nice to know. Thanks.
good informative video thanks
Great content very informative just what I was looking for.
Awesome, thank you!
Will an incorrect float height create a lean running condition? I recently replaced 4 floats on a Yamaha F100. I was getting a lean sneeze around 2800-3200 rpm. Inspected the plugs and saw #1, #2 and #4 running lean. I’m thinking the float height will need to be looked at again. Idling great, and high speed boat runs great. I was thinking of enriching the idle mixture screw to compensate, but I think I’ll tear it down again and make sure floats are set correctly, as they should be.
Very very good!👍
Thank you for awesome video, I have 2001 Yamaha T50TLRZ I’ve have clean the carbs, where do I start setting the air/ fuel mixer at some forms Start at 2-1/4 on carbs 1,2 and3, 4 carb at 2 1/2 turns out? Do you know where it should be. Thank you
My f25 Yamaha 4S without a spray of starting fluid. Which circuit needs cleaning pls?
How do I get the plug out that covers the air fuel mixture screw?
Thank you very much for such detailed explanation of how all these works. I have 2004 F90TLRC, new to me. Low hours and clean carbs. It idles at between 9000-1000 when warm. Spark plugs are dry and more on white color(all 4 plugs similar color), indicating lean mixture. I am trying to avoid possible overheating and want to run engine in optimal way. Dont have starting problem or power at high RPM/speed. Engine runs and responds fine. I put about 20 hours on it with no problem.
Questions:
1.Do these engines tend to run a little lean(emission regulations) and I do not have to worry about plugs being not tan in color?
2.Do I want to play with butterfly screw on bracket to bring RPM down to 800ish? May be play with idle muxture screws? But there are 4 of those and I do not want to mess existing setting.
Thank you very much in advance. Any thoughts or suggestions will be greatly appreciated.
Hello Ilia.
If you are not experiencing lack of power or driveability issues, (surging, etc) at WOT fully loaded then I would not be concerned about very clean spark plugs.
I would definitely adjust the idle speed down. I don't have the Yamaha recommended idle speed handy, but 900 to 1000 rpm sounds a little fast. The bast way to adjust your idle is with a carb sync vacuum gauge setup. A vacuum gauge connected to each intake manifold runner so that all four carbs are balanced.
@@CanadaWideMarine thank you very much Sir for such a detailed answer. It is exactly what I wanted to know. I was thinking to invest in carb cync tool and you just made it easy for me. Yamaha says 850 is recommended RPM. So I will play with that. Will report here as well. I also downloaded factory manual, but it does not describe too much about working on engine. And I am a subscriber now.
Thank you great informative video. My question is at what RPM does the idle function stop and you go on the main circut. I have a 20 HP Honda that idles fine and runs great at mid range and WOT but trolling at 1000 to 1200 RPM the engine stalls but restarts instantly. Sometimes this happens every minute and is frustrating. I have an inline fuel filter and that was clean. It gets a great squirt of gas from squeezing the inline fuel pump. The plugs look great. Any direction would help thank you
The idle circuit operates in 2 stages. The first stage, is complete idle, with the throttle fully closed. The second stage is called the transfer stage, it operates through about the first 5 degrees of throttle opening. In the transfer stage you are getting a little extra air coming past the throttle blades, but not enough to start the main circuit flowing.
That little bit of extra air draws fuel out of the transfer holes that you can see just behind the main idle hole behind the throttle blade. This extra fuel comes from the idle circuit.
So at trolling speeds, 1000 to 1200 rpm you are most likely still on your transfer stage of the idle circuit.
To remedy this situation I generally richen up the idle mixture screw a little, about a quarter turn counter clockwise usually takes care of it.
You may have to remove the cap over the idle screw. Some older Hondas have an idle screw with a limiter stop on it which can be a problem. open it up as far as it will go.
So easy, thank you : )
You're welcome 😊
I have 20 hp yamaha four stroke and on full throttle engine rpm flying high and lows. what's wrong?
Full throttle fluctuations in engine RPM are often caused by a lean mixture, slightly restricted main jet, vacuum leaks low float level, restricted fuel filter or fuel supply, air leaks into fuel supply. Other causes cold be bad spark plugs, weak ignition system, Poor quality electrical system, check grounds in particular, but also all battery connections and battery switch etc. Even a corroded battery switch or kill switch. In summary, there can be many causes and it is impossible for me to say what is wrong without diagnosing the issue myself.
@@CanadaWideMarine thanks!
Thanks awesome video
Other than the float needle what would cause fuel to come out of the overflow?
Fuel comes out of the overflow because there is too much in the float bowl. Many small outboard carbs have a fuel inlet in the bottom of the float bowl, with a passage through the float bowl into the main body of the carb where it the goes to the needle and seat. That passageway is sealed between the main body and the bowl with the float bowl gasket, (which is actually a formed rubber o ring). If the float bowl gasket seal is not sealing correctly you will get too much fuel in your float bowl through the leak in the seal into the float bowl. Other causes of too much fuel in the float bowl could be incorrect float level, sticking float, (not moving freely), or a sunk float usually caused by the float filling up with gas from a leak into the float. Give the float a shake and you will hear liquid in it if this is the case.
Hi there my Yamaha 2007 T 9.9 it was running only with the chalk little bit out. I can drive it that way, but as soon as I put the chalk in it stops I came up to your video which is one of the best I watch lately thank you for your good work I took my carburetter apart the way you showed when I came to the idle jet, somebody’s been there before me and broke that slot for the screwdriver. I couldn’t take it out so I decided I’m going to use a small easy out to pull it out. I was doing good but soon got hart to turn it but all of a sudden got tight and I didn’t succeed. Is it anyway that this carburetter can be used by drilling and doing something else so I don’t have to buy a new one. Please advise what is my options? Thank you.
you could try heat. get the carb body really hot before trying the easy out again. The heat expands the aluminum body and may loosen the jet in the body.
Hi.
Thank you so much for the create video explanation how the carb works. I am actually very interested in the mecury carb plunger (video 19.12 min) could a wrong adjustment of it also make the engine run rich? Ive adjusted the airflow and got the engine run in idle very nice but sparks are dry black. Carb is cleaned and Checked the needle like you showed upside down blowed and it seals of nicely no leaking. I cant get my head around why the sparks are black every time after I tripple checked it and adjusted it. Greetings from Holland. Davis.
If you are getting black spark plugs it is usually a sign that the engine is getting too much fuel.
Now, I need to assume you are running the correct plugs, and new plugs. Engine oil has been changed recently. (old oil will foul spark plugs), Compression is good. Also assuming the main jet is the original. That leaves float height. If the float level is too high, even just slightly, it will allow he engine to get too much fuel.
The accelerator pump adjustment will not affect mixture, it only operates when the throttle is moved.
I'm trying to remove the old accelerator bellows boot to install a new one
Thank you for the information, I have 40hp 4 stroke and I have had the engine not speeding up no matter how much gas I put on so I thought it's the carburetor and got it off cleaned it and replaced it back but it's still the same ,
I'm thinking to buy new jets
Any site recommendations ?
Maybe you think I have a different problem?
Thank you in advance
My advice would be to have your motor diagnosed by a reputable marine mechanic before spending money replacing a carb that may or may not be the problem. It should only take an hour or two for a good mechanic to thoroughly diagnose your problem and advise on a course of action to repair.
Without seeing the motor in person there is no way I can possibly identify what might be wrong with it.
Thank you very much!
You're welcome!
I have a 25 4 stroke tohatsu with 3 carbs.I assume i will have to clean all 3.it will not idle.
I would clean all 3. I also flush the fuel lines from tank to carbs to make sure I am only getting clean fuel to them after cleaning.
@@CanadaWideMarine do you recommed a fuel water seperator
Yes. I almost always recommend a water separator. They can prevent a lot of heartache.
Great video! I do have a question about my Yamaha 40 Hp 4 stroke, I have a diaphragm assembly and there is a spring on there that wasn’t engaged I think I put it on right but now I need to adjust it so it works in accordance to the throttle
I'm not sure which spring and diaphragm you are referring to? You are welcome to email some photos to support@canadawidemarine.com and I might be able to help you out.
I have learned quite a bit by watching your work. I have a 1999 Evinrude 6RL4EEM 99, 6 hp, 4 stroke. The carb has an accelerator pump on the bottom, which water flows through. Have you ever seen a carb like that? There are no parts available for the accelerator pump, but the carb kit is available. The engine bogs upon acceleration but otherwise starts and runs good. I haven't rebuilt the carb, but took the carb off the motor and took the float bowl off and it's very clean inside. Is there any sense in rebuilding the carb since I can't fix the accelerator pump? Also, the motor uses a very rare fuel pump. No rebuild kit available and a replacement fuel pump is $166.00. It's a good little motor used on a sailboat. When docking, sometimes you need a little rev and that's when the motor bogs and sometimes dies. Not sure what to do. Thanks
This is the problem we are seeing a lot of these days, parts no longer available for older motors. Is your accelerator pump diaphragm leaking fuel? if it is then you have a fire risk of course, if it isn't then we need to look into why the motor is not getting enough fuel on quick acceleration. a dirty or sticky check valve on the accelerator pump is a good starting point. an air leak on the inlet side of the accelerator pump is another, (when the pump is re-filling it can suck air instead of fuel sometimes). another thing that might help is to richen up the idle mixture a little bit, or raise the float level ever so slightly. I assume a new diaphragm does not come in the rebuild kit?
Tough choices with an older motor, we have had to scrap many motor for lack of parts available to repair them. And I think the problem is only going to get worse in the future.
@@CanadaWideMarine Thanks for the quick reply. I don't see any fuel leakage from the accelerator pump. I do see 2 little check balls/valves inside and they are both clean and free. The diaphragm seems pliable. The carb kit does not contain accelerator pump parts. I can see someone has been inside the carb because they stripped the drain plug in the bottom of the plastic float bowl and also one other screw by the accelerator pump. I will fix these issues, spray some carb cleaner and test again. I will try your suggestion on the idle mixture.
Do you know if my fuel pump 0445078, might be compatible with any modern pumps? I don't want to mess with it at the moment since I can't get parts and the price of a new one is ridiculous. Thanks again
That would be a question for an Evinrude dealer. We don't see a lot of Evinrudes in this area so I am not overly familiar with those types of details.
@@CanadaWideMarine Ok, thanks for your time. FYI, upon further inspection I now see the little diaphragm for the accelerator pump is split. Since the part is no longer available, I made a tiny gasket that fits under the entire diaphragm out of inner tube rubber as a test and I can get it to pump water. So I ordered a sheet of thin nitrile to make a permanent fuel proof gasket. Haven't tested it running yet, but I think I have a chance. "It's amazing what you can do when you have to do it"
Hi, I am disassembling the carb assy. on my 2001 Yamaha 50 HP 4 stroke. Can you tell me what the trick is to releasing the link rod bridging the 4 carbs and also the link rod from the accelerator pump at the carb end? Both parts seem to be snapped into place, no cotter pins involved. Is it a matter of pulling at the joint to release? I don't want to damage anything> Thanks again for all your great videos and explanations. Jim Murphy
Hi Jim,
Yes, you got it right, the linkage snaps off. I usually use a pair of needle nose pliers to get underneath the linkage and pry gently against the arm so I am not bending the arm as I pull the linkage off.
Thanks for watching.
@@CanadaWideMarine Thanks again. I'll carefully give it a go.
Thank you very much for this great explanation of how carburettors works. I have a Yamaha 2002 F60TLRA from new with 1800 engine hours, it is a trailer boat used in freshwater for walleye and lake trout trolling.
The engine is hard to start when cold or first time that day, it normally stalls a least 10 times before it runs fine . I suspect it is caused by a vacuum leak in the prime start system, (as you describe in the video) i also idles a little bit rough around 700 to 900 rpm. i plan to rebuild the carburettors with 4 new carb kits.
When the engine was new i had a lot more power (same boat not much added weight) i know that it is quite common that engines lose some power with time, but i am wondering if it is possible to gain some power back?
Spark plugs are dry and more on white colour (all 4 plugs similar colour), indicating lean mixture. I am wondering if new larger main jets would yield more power in the mid range 3500 to 4500 rpm?. . Thank you very much in advance. Any thoughts or suggestions will be greatly appreciated.
Sorry, for the delay in the reply Lars. I replied to your other comment so hopefully that helps.
Good video! Why is the pilot circuit part of the main jet ? On my motorcycle, they are separated.
On some carbs they are indeed separate. It doesn't really matter because at low speed when fuel is metered through the pilot jet, or idle jet, the main circuit is not functioning, so the only fuel going through the main jet is for the pilot jet, (if they are incorporated together). At high speed there is no fuel going through the pilot jet so it does not take away from the main jet metering. Hope that helps
@@CanadaWideMarine Thank you for that explanation!
Thanks for that good video and the explanations. One question: to follow the pipes, you put what in? Which spray is this? If I understood correctly, also WD40 works but do I than have to clean the carb again because of the oil? Or does the oil not harm the working of the carb? Thx a lot for your help.
WD40 would work just fine. In fact WD40 is a bit of a solvent and will help clean the internal passages. Blow it all out and off before final assembly. a little residue from the oil will not harm anything.
@@CanadaWideMarine Thank you so much.
Can I remove the welch plug covering my idle mix screw? It doesn't need to be replaced after either? Great video, I learned a few helpful things, been tearing carbs apart for 30yrs as an amateur, lol.
Hey buddy, yes you can, but be VERY CAREFUL. You need to drill a hole and pop it out. Its a little brass plug. Stop drilling when you hit another piece of metal. That would be your mix screw
Orlando beat me to it, great answer. Yes, you absolutely can. I generally use a 1/8" drill bit to put a small hole in the plug, then tap a #8 self tapping screw into it. being careful to not screw it in too far and damage the mixture screw in behind the plug. Basically don't force the screw, just in enough to get a bite. Grab the screw with some pliers or vice grips to pull the plug out.
And no, you do not need to replace the plug after. The plug is there so people cannot richen the idle up to meet emissions requirements.
Thanks for the replies. It was round 2 for carb clean, 1st time didn't work, but it turned out to be those pin holes in the idle jet, reamed out with my guitars high e string and im back on the water! Spring salmon are here and motors running perfect. The video saved me! But I might still pop that welsh plug, I dont really like it🙂
Welch plug, not welsh plug🤣
Very good video. Question I have a 2011 90 Hp Mercury 4 stroke. My will take off from idle and get on plane and run for about 200 yards then bogs down. Do you think that the float is sticking and not allowing fuel to enter the bowl or something else?
There are many things that can cause those symptoms. I would start with checking the whole fuel supply system. Looking for restrictions or leaks that can allow air to be sucked into the fuel line
is there a screen under the needle seat ? having trouble blowing air through to the bowl even without the needle in . having a hard cold start but runs well after i get it going . 03 8 horse 4 stroke yamaha with nikki carb
There is no filter screen under the seat, but you could have something lodged in there before the seat. Have you tried blowing backwards with air pressure from the needle side?
ON an older motor like that with hard starting cold, assuming plugs, compression and all the basics are in good shape I would start looking at the carb to manifold seals, they get hard and flatten out so they leak a little air when cold.
I've cleaned my carbs out good and changed fuel lines. My issue is when I gas it and let off it dies. If I go slow she'll power up. It's when I come down from throttle it cuts.
There are many possible causes for that type of issue. I would recommend a proper diagnostic by a marine mechanic. The diagnosis is almost always cheaper than just replacing random parts until the problem is solved. I could suggest a handful of things to check, only to find the problem is something I didn't mention and that doesn't help anyone.
Sounds to me like an adjustment issue on your carburetor setting. They have air fuel mixture screws it's not receiving the proper amount of air or it's being bogged down by too much gas that is most definitely your problem and if it's not that it could be a vacuum leak or the actual teeth that hold down the float Bowl regulator they do tend to bend upward and allow too much fuel sometimes just the side note took me a while to find that one time
Got a hole inside of my carburetor Yamaha 25 I got fuel coming out of it
I have the 9.9 prokicker and the boot on the enrichment port is leaking. I cant find a single vid on rebuilding this component. Anyone?
I am assuming you mean the boot on the accelerator pump. This is caused by a cracked diaphragm, very common. As you disassemble it, keep track of the location of the springs, and it is pretty easy to replace. The diaphragm does not come in the carb rebuid kit, you must buy it seperate.
Hi
Greetings from Australia
Got a 2016 suzuki 8hp 4 stroke outboard
How many carb adjustments for this motor pls ?
How many turns out for base speed for full throttle top speed performance pls ?
Thanks
Glen
Australia
Hi Glen, I spent almost 20 years in Australia, it treated me well.
There are no adjustment screws on your carb that will affect full throttle performance. Full throttle mixture is adjusted with the main jet.
Now, if you are experiencing a lack of performance, a running issue at full throttle, many things can cause that. Just with the carb poor full throttle performance can be caused by a restricted main jet, incorrect float height and drop, vacuum leaks. Other causes of poor performance at full throttle can be bad spark plugs, weak ignition system, weak electrical system etc.
Good day, If you can help. I have second carburetors that you show, Mercury, Tohatsu. ITs overflow on idle. I clean all 20x times, needle is sealing, but still on idle it overflow after 10 seconds of working. Thank you upfront.
If it has the fuel inlet in the bottom of the float bowl you likely have a leaking float bowl gasket. It leaks fuel from the inlet passage into the float bowl.
Hope that helps. Thanks for watching.
@@CanadaWideMarine I want to thank you in my and my dad name. You help us a lot. You explain how FLOAT should stay. Yesterday according to knowledge that you gave us I check float level with brand new spare parts and saw that is wrong. I put back old parts and now all things are fine. Thank you 100 more times that you help us.
Awesome
I have a automatic choke dose it make it harder to clean and disassemble john
Not really, no.
I recently cleaned my Merc. 15hp 4 stroke carburetor. I’ve no leaks or purging. Seems to run as should. However, the primer bulb on the motor itself, not the fuel line primer doesn’t get firm. Any idea what the cause could be?
Most likely the valve in the primer bulb. Replace the primer bulb is an inexpensive fix.
I’ve got gas coming out of the breather line for the accelerator pump on a 08 merc 20hp 4stroke, is that common when the plunger doesn’t seal anymore?
Yes, it sounds to me like you have a leaking plunger.
Great video , do you any online resources for ajusting a suzuki 9.9 four stroke carb thanks.
I have nothing Suzuki specific, but watch for an upcoming video on general adjustments of idle mixture and speed. Float level is covered in this video.
Thanks for watchng.
what is the best way to remove varnish from the carb? carb cleaner doesn't do it. terry clark
Hi Terry, I've had good luck with lacquer thinner. Soak the carb overnight in it should soften the varnish up.