Wow you are good teacher. Thanks. I am having issue on a ttr110 tried different jets to control bog at full throttle but now I have good ful throttle but no idle and when I change pilot I get full open bog I'm so confused can't get both to be right. I have a air screw and a welch plug do I have both air and fuel screw? I thought u said there is only either or.
I also use spark plug color as indicator, trying to aim to a brownish color. Starting from being too rich with carbon black spark plugs making adjustments down and always running the bike for at least 30 minutes, with highway parts and check again color until right. It can take several days but it seems the most precise method without the use of fancy tools, what do you think ?
As far as carb adjustments, this is definitely the best video ive watched so far. Also explaining how it works. Thanks a bunch. I feel way more comfortable going foward with my 1st attempt
I was a tech in a Yamaha dealership back in the eighties and Yamaha said we had to adjust all carbs while using an e-gas analyzer to spec, always too lean, and replace the plugs or they might void warranty. Honda wanted us to do idle drop adjusting which honestly worked much better and no expensive, delicate equipment needed
My bike doesn’t seem to have powerband or the full power it has it kind of feels like too much air or something but before it would bog and just cut off but the bike is a 2022 yz85 and I’m confused it went from fresh to not I cleaned the jets and I tried to mess with the floats and even then out with the top of the carb and cleaned the air filter and changed the spark plug if I don’t know what to do I’m sure it has to do with the carburetor
Why would the pilot screws have to be a 1/2-1 turns out? Both are the same and it just revs higher as I turn screw in, it doesn't bog down till I turn it out around 1/2-2+.. please help me when you can. Thanks!
@@Muchteba if no powerband try check your powervalve, it could be stuck with too much carbon buildup..after riding at wide open throttle for about 10-20 second, immediately stop the engine and remove the sparkplug to inspect the colour to see whether its too rich or lean..
On a twin carbs bike, the pilots screw adjustment need to be the same or it can be different from carb # 1 to carb # 2 ? Like 2 turn out on the carb # 1 and 2.5 turn out on the # 2 ?
Thanks man, great explanation on how it all works. I recently resurrected an 86 vmax that had sat for 10 years, bad gas, rusted tank, frozen carbs, etc. Runs great at upper rpm but won’t idle without choke. I should have removed the factory set pilot screws before I soaked the carbs, as you mentioned, probably the issue. Going to do it now. My thinking, since only has 5k miles, was that factory setting probably correct. I might even see about getting larger main jets, but the thing is insanely fast the way it is.
This is a good video. I hope between both your videos and mine, maybe people might start to understand how to do this on their own. But still I think people don't want to spend the type testing, changing a setting, testing, and so forth.
Thanks. Tuning can be a PITA, however with this circuit the answer is in the screw setting. Don't even have to ride it to determine if it is lean/rich.
Right, but novices I think lack the analytical mind we may have. This video builds on our previous information around the topic. Too bad it can't be better centralized. I have tried to do that on my website, and I might embed your video there.
@@HTMR my vtx mixture screw was completely burned out and crudded up with rust and kept playing with the mixture not realizing till I dug deeper and once I cleaned it up it was much more responsive but now I’m dealing with slight hesitation during acceleration using barons set with 210 but they didn’t assign numeric value on pilot
I'm impressed with your knowledge and ability to teach. Taking the time to illustrate the theory is top notch stuff. I learned a lot, and really appreciate the time and effort you put into creating this video. I have an '86 Ninja ZX600R, purchased in '90, and it's always suffered from being too lean in the pilot circuit, and falling on it's face when the throttle is rolled on. I've had the carbs off and apart for cleaning, probably 3 times since purchase, (learning more as I go along in life) mostly due to leaving it sit unused for long enough that the fuel went bad in the carbs, but I didn't know about how jet sizing has an effect on mixture ratio, even though the pilot screw might be out enough that they idle is good. I've even synched them, and although there was a noticeable improvement, it's never be perfect. I'll be I could go a size or 2 up, and cure the issue, if any company is making jets still. Thanks again!
You might have just saved my bike. Stay tuned! Thanks for taking the time. The most informative video on the subject that I've found. I can't wait to get home and try this.
Great video, very comprehensive. After removing the welch plugs on my '94 Kaw Voyager 1200, I discovered that two of the pilot screws were buried (zero turns out) and two were about 1.5 turns out. The plugs looked factory, so it's shocking that Kaw (or Keihin) would have messed up so badly. The guy I bought the bike from told me that it was originally sold in CA, so maybe that has something to do with it.
Wow excellent Matthew, I have been mechanic on these for 55 years but some mixture screws didn't give me the proper response..you have taught me how to better decide the pilot jet configurations..Who says you cant teach an old dog new tricks..lol Oh by the way..the carbs are already synchronized before this video?..Yes? Liked and subscribed..thank you very much. Peter
my xtz 750 SUPER TENERE IS 2KILINDRE PARALER AND if some working lite difrend about valve change not need maybe to one calbulator difrend turns???? for exaple one calbulator 3 turns and second 4 turns??? or allways need be 3+3???
Watched tons of videos trying to figure out what i need to be looking for, for my carb and no one has explained it as clearly as you do. It all suddenly made sense.
Hay, HOW-TO. You made mentioned the popping sound in your audio. I know what it is. Someplace on that bike, the spark is jumping to the ground. Check the wires and boots.
So I have a honda vfr750fk rc24 1989 I have carbs set to 4 and abit turns out runs lovely ticks over lovely I ride it atleast like 100miles and then pulled spark plugs out and showed a garage and they said it is running fine so I put them in let them have a go on my bike and they did a 3rd gear low rpm pull and it just picks up no flat spots or enything
Honda vfr750fk 1989 got stanles steel down pipes in to exhust can no baffles hight lift cams and tuned engine carbs are 4 and abit turns out but runs lovely spark plugs look good is it too much
I am having a big trouble with my yzf 600r thundercat. He idles just okay when it is 2.5 turns out on 1 and 4 and 2 each on 2 and 3 from left. But i can smell it is really rich. It has stock jets. Doest have a a fuel screw it air screw. I thought it is leaning out when i turns it out🙄
After hearing it I can tell you that the popping on your audio is caused by rf interference from ignition system discharges effecting the electronics in your audio equipment.. Better audio curcuitry should have better shielding against it. Also possibly some form of suppression/filtering on your ignition system but I don't know if that can be done.
Already liked that video last year when I found it, looking for info about carb and rebuild and tuning but want to say thanks again since I completely rebuild both of my 96 1100 Virago carbs and currently having some issue to tune it well. I looked and dozens of videos but this one, I I look at again, clarified everything. You are very clear and really take the time to visually explain how the carb works. Thanks man! really nice work!
Hey man thanks a lot man I have Ben putting back a Yamaha 2006 r6 for 3 years now..it was throttling good and reving good..I had replace some head o rings n start the bike n it stop reving and a wile after it start to missing n he other thing as well the throttle body get tight..I take the plugs our clean them n free up the throttle body as well n check all wiers n all is good knick ..thanks a lot man n I'll try the 3 turns out n see what..keep what you do best by Charing your nalage..👍💯🔐
Thanks you MatthewMCrepair for making this videos and helping us out. I have one question. I have CBR 600, 1998 and it runs great on the streets but idle sometimes drops below normal point. Smell from the exhaust is really hard (gasoline) all of the pilots screws are 2.5 turns out (somebody before has messed with the carbs). I have taken the spark plugs out and found that number 1 and 2 are really black. 3 and 4 seems to be OK. Should I try to put number 1 and 2 let say 2 turns out and leave number 3 and 4 2.5? Or should I lean all 4 of them a bit and see how it runs? Thank you in advance and greetings from Croatia.
I have Mikuni VM26SS carbs and they have both fuel and air screws Just thought I'd point that out to ya but great info u always give and keep up the good work 👍
hi my bike is running rich .plugs are very suity at 3.5 turns out .this sets the fastest idle.would I go down one size with the pilot jet and main jet so it runs a little leaner 🤔
I think that 3 turns out may only apply for CV carbs. The Amal and Mikuni need to be about 1.5 turns. I got an old GP Amal that has the air screw on that engine side. One side effect of running too lean a mixture is that the exhaust pipes can colour up, as happened with my Royal Enfield.
So if the aim is to get the smoothest fastest idle speed why did you lean it back down from 4 to 3 turns after pionting out that it had smoothed out at 4.i don't get that. Oh wait yes I hear you so once it smooths out it just stays like that does it and wastes extra fuel unless you trim it back to where it only just runs smooth.... Is that right?
QUESTION, please (5 years later!) - How to know when your Pilot Fuel Screws are SEATED? When screwing in, the spring begins to add tension... but this is very soft and gradual. In theory you could twist that screw in a long way, using a lot of torque. SO- What is "SEATED" and how can you find this?
Hi you mention on the fuel screw, pilot jet, if it’s under one turn or maybe under two turns it’s too rich, but that doesn’t make sense as if it’s a fuel pilot screw, the more you turn it out the more fuel your adding, therefore surely if you turn it out for less than one turn, it’s too lean, and not too rich, it will only become richer the more you turn it out.
I have a 1980 yamaha xs1100 special and I have been having issues with setting my idle after rebuilding the carbs. this whole video gave me sooooo much help in understanding how this system works, I thought I had an air screw, turns out its a fuel screw. I'm an automotive tech and never messed with bikes before now and I appreciate how in depth you got explaining this.
Oh, " and I also just made this number up" lol....regardless...I just took some of your advice! Very nicely done btw! I've ordered two Main jets size 125 , two Pilot jets size 42 and 2 shim for each Slide Needle for my 84 750 Shadow!
My problem is I have new mikuni rs36-d8-k carbs on my yamaha xj1100 amd jetted for the engine and per directions it says to turn them out ⅛ to ½ turns out max but it doesn't say from a light seat, fron a turn out, or anything in the directions. A light seat is something that is hard to determine because it is seated against a oring and each carb has a different feel and look when you look at each pilot jet screw with the carbs off so I've ordered a colortune to see where thigs are at. Your video is a great watch for sure and explains things perfectly.
Can i get your opinion. I have gsx 750 f 2001 with slip on. I just got dynojet jetkit.On the basics it says that with slip on put 114 main jet,dynojets needle to pos 3 and all the pilot jets screws 3.5 turns out. Before this i had pilot screws in 2.5 in cyl 2 and 4 and on 1 and 4 3 turns out. Bike worked very nice but i thin it was little bit lean. I put the needle to pos 5 and now it work worst than the factory instructions. So should i put needle back to pos 3 and put 3.5 to pilot screw
Thanks, great video. Each time you said you were turning 1/2 turn you actually turned a whole (1) turn. What's up there? I thought each carb should be adjusted individually. There may be variation in the carbs and engine that would require slight differences, don't you think?
@@BasicPoke I am a bit late to the party lol. But the first one where he stalled it out he did a half turn out then a half turn back in. It looks like a full turn at first. The others were full turns I believe to reset things.
Hello! I would like to ask a question. If you might can help me. Bike is Yamaha YZF R6 2000. When I speed up with bike it rattles a lot and there’s black smoke coming out from the exhaust. Bike isn’t running perfectly when it’s in neutral. What might be the issue? Sincerelly, Mika from Finland
At 1:35 you say that a carb will have either an air screw or pilot air screw, but never both... Mikuni VM fitted to Suzuki GS motorcycles from the mid 70s thru to the early 80s do.
Vid is prob too old to get a responce but why does the service manual for my Yamaha YZF600R state to put the screws at 1 3/8 th turns ? Is that because it's a CA spec MC with smog rebreather ?
5 minutes 45 seconds in, you apologize for audio popping. Did your spark plugs have resistors in them? Does the spark plug number have an r on it? It can interviewer with your audio if it did not have a resistor.
Hi i have a tgb target 525 . 503 cc engine. This use a mikuni carb BSR 33 (33MM DIAMETER) and i wanna ask what is the best jet combination to get max power and high rpm( 9.000...10.000rpm) .from the factory this came with .225 PILOT JET and 145 MAIN JET and at the moment is runing a ignitech cdi unit witch is programable and no rev limited. Thank you.
Hi, there i have a 1100 yamaha dragstar. Bike goes well, but everytime i stop the revs stay way upthere for a couple of seconds and then comes down back to idle mode. What could be the problem. Can anyone help please
hello!great work!i have a suzuki freewing xf 650 no exhust (im planninig to install)but open airbox..for sure going faster accelaration and sound but donst work perfecly..i was thinking for some jet kits tuning...please i need your help...thank you in advance 🙂
1997 vlx600, removed exhaust baffles and VERY restrictive airbox and filter, it became so lean it wouldn't come off idle, went from 40 to 45 on pilots and 115 to 155 on mains and raised needle height on clip position. Runs MUCH better but screw adjustment is 2.5 turns out on left carb and 3.5 -4 turns out on right! Any ideas on why such a difference?
thanks for the video. Ever experience a pilot screw that is stuck and won't come out. I got it broken loose and it backs partially out the bore but they just spings and doesn't fall out. Any ideas how to get it out?
Use a thumb tack and put pressure on it from the carb bore. Make sure the tack does not enlarge the orifice in carb body. Make sure threads are clean first.
I have a kawasaki zr7 750cc, carb is cleaned but I’m confused with the idle screw. This morning I had a ride, at traffic the rpm went up all of the sudden. What does that mean? My idle screw as at 2 turns. My carb is Keihin CVK. My jet size is 108 and screw is 38.
Hy, a sport exhaust can influence this settings?, and how? I understand that this settings you presented are made with the genuine factory exhaust. Please do explain this in a video.
On this radian with pods, did you change needle position or main jets? Or just pilot jets? I have an 86 radian I just put in a 6sigma jet kit which has 35 pilot. It idles good but as soon as I start to roll throttle it dies. Sounds like a bog but it dies so fast its hard to tell.
What if I only have one screw on my carb in the middle? And I drilled the plug out by the fuel bowl but there's nothing in the hole but another closed piece of metal?
Ok, i know these are motorcycles, but mikuni tm flatslide carbs on alot of snowmobiles have both fuel and air screws on the pilot circuit. I would love to know the procedure to tune those correctly.
Hello! Thanks for the detailed explanation! We are also in the the process of the tuning the fuel screws. Two questions if someone knows to help out 🙏 1. Before starting the process, where should be the idle revs configured? High, low or manufacturer suggested? Or something else? 2. What happens if the screws are in a location where it is probably impossible to tune them while the engine is running. Any tips and tricks? P.S. The bike we are trying to tune is Honda Cbf 600, 2004. Thanks!
Hey bro. I have an ltz 400 Mikuni carb with Main jet 140 Pilot 25 How many turns out my air fuel screw should be? Also what level the needle clip should be on?
Thank you for this video and explaining this in depth. I have a 08 kawasaki teryx with the 750 and I don’t think the carbs have ever been set right for the riding terrain here in Oregon. So again thank you for taking the time to help
I have a question.. I bought a yamaha road star silverado 1600. Year 2000. It came with aftermarket exhaust, but only had regular filter and carburetor not adjusted. I was getting 46 mpg because the bike was running lean. Now I put a Dyno jet kit and K&N air filter. Now I'm getting 34 mpg. Is that normal? Also when I turn on the bike when cold I dont need choke and after warming up for a minute, I try to rev it quickly and feels like it chokes up, but if I wait for it to warm up for 3 minutes that won't happen. Is this all normal? It was backfiring when down shifting and deceleration. Now with this tune it doesn't do it which I like. It live in a desert environment at 3,000 ft of elevation. Thanks
So i got a 1995 honda VT700C for my son in law not running cleaned & bench sync carbs idles like a champ but if I put it on center stand runs great shifting through gears, issue comes when I go to ride it, it bogs down sputers chocks, you have to let off a little then slowly roll into the throttle every time you shift and even then it will sometimes bog out I'm at a loss please help!!!
Just stumbled on you channel oh boy you just have answered a annoying problem with my 1990 ZXR750H2 (uk) my idle is slow to return to normal I do have mods I'm running micron headers to a SP stubby can with K&N filter im running 130 main jets high speed running is spot on. I do sometimes have a problem with the bike cutting out when hot at traffic lights your explanation of the pilot jets which I have set at manufacturing setting one and three quarters turned out looks like I need to turn them out further looks like mine is running lean and the fuel is evaporating before its pulled into the engine . I have uploaded a video of my bike to my channel me revving it and you can plainly hear the rpm slowly returning back to normal idle. Great video your never to old to learn thankyou so much for this video. Happy New Year and I hope 2021 is a good one 😎👍 ps you have a new sub
I’m pretty sure that I could have done the valves myself and got it running sweet but it was well worth the money spent for piece of mind that it was done right. In fact the guy that did the work rides a Radian also. He said he was jealous at how nice my bike ran. I guess I got a good one.
BEST VIDEO ON UA-cam! QUESTIONS: I backed my idle screw all the way out on my vtwin 1100 vstar, and it still idles at around 800 RPM. When I lean it out idle goes down and when I richen it the idle goes up. But where it idles smooth and fast is too fast for the lowest idle screw setting. Also, note that when I close the AF screw all the way the bike still idles and will not stall even with the AF screw all the way in on the front cylinder. Also not that the rear cylinder AF screw has no real effect to any change I make to it, except the backfire pops, when I lean it out and less backfire pops when I richen it, but it does not have any real effect at idle. Only the front carb seems to affect idle. I bought this bike second hand. I think its time to ditch the carbs and buy another used set and start over?
Well. . .I have looked and looked and this is so helpful, beats everything I've seen, so very well done and much appreciated. I could use a few minutes of private tutoring, are you available?
You mentioned audio popping 5min. 40sec. into the video. That would be due to the fact that your spark plugs do not have resistors in them. Without the resistors your spark plug wires become antennas that broadcast a radio wave.
Really want to thank you for all your very informative video's, I recently bought an 82 XS 650, and since then I have learned how to make noise out of money!
Pilot jet explained blog post - www.howtomotorcyclerepair.com/how-to-size-your-pilot-jet-pilot-screw-explained/
Aux fuel tank - amzn.to/2WJboTy
Can you make another video showing where the carbtune vacuum hoses being inserted?
Wow you are good teacher. Thanks. I am having issue on a ttr110 tried different jets to control bog at full throttle but now I have good ful throttle but no idle and when I change pilot I get full open bog I'm so confused can't get both to be right. I have a air screw and a welch plug do I have both air and fuel screw? I thought u said there is only either or.
Royal Vintage Spare A112 Auxiliary Fuel Tank For Servicing Your Bike 300Ml
"Every jet size is a 3 - 5% change, approximately, and I also made that number up." And subbed...
I did the exact same thing
Wow. Amazing tutorial. Your description of the air vs fuel metering pilot screws was extremely helpful.
I also use spark plug color as indicator, trying to aim to a brownish color. Starting from being too rich with carbon black spark plugs making adjustments down and always running the bike for at least 30 minutes, with highway parts and check again color until right. It can take several days but it seems the most precise method without the use of fancy tools, what do you think ?
As far as carb adjustments, this is definitely the best video ive watched so far. Also explaining how it works. Thanks a bunch. I feel way more comfortable going foward with my 1st attempt
You not listen to any other explanation. This guy teaches well explaining and showing what to do
Im working on a carburettor at the moment .the bike is idling at 5000 rpm
This popping sound is your microphone picking up ignition coils/spark plugs running
This is one of the best explanation when it comes to A/F mixture, kudos man!
It is hard to follow when you are only talking about a fuel screw, so does everything you say opposite if you have an airscrew.
I was a tech in a Yamaha dealership back in the eighties and Yamaha said we had to adjust all carbs while using an e-gas analyzer to spec, always too lean, and replace the plugs or they might void warranty. Honda wanted us to do idle drop adjusting which honestly worked much better and no expensive, delicate equipment needed
My bike doesn’t seem to have powerband or the full power it has it kind of feels like too much air or something but before it would bog and just cut off but the bike is a 2022 yz85 and I’m confused it went from fresh to not I cleaned the jets and I tried to mess with the floats and even then out with the top of the carb and cleaned the air filter and changed the spark plug if I don’t know what to do I’m sure it has to do with the carburetor
Why would the pilot screws have to be a 1/2-1 turns out? Both are the same and it just revs higher as I turn screw in, it doesn't bog down till I turn it out around 1/2-2+.. please help me when you can. Thanks!
Hanes manual says the same thing for Kawi
@@Muchteba if no powerband try check your powervalve, it could be stuck with too much carbon buildup..after riding at wide open throttle for about 10-20 second, immediately stop the engine and remove the sparkplug to inspect the colour to see whether its too rich or lean..
Got a bran new carburetor and it boggs out got a 1991 4x4 kawasaki bayou 300 4x4
just bought a 1980 KZ750 I’m working on getting it running thanks this has been helpful
On a twin carbs bike, the pilots screw adjustment need to be the same or it can be different from carb # 1 to carb # 2 ? Like 2 turn out on the carb # 1 and 2.5 turn out on the # 2 ?
Thanks man, great explanation on how it all works. I recently resurrected an 86 vmax that had sat for 10 years, bad gas, rusted tank, frozen carbs, etc. Runs great at upper rpm but won’t idle without choke. I should have removed the factory set pilot screws before I soaked the carbs, as you mentioned, probably the issue. Going to do it now. My thinking, since only has 5k miles, was that factory setting probably correct. I might even see about getting larger main jets, but the thing is insanely fast the way it is.
Yeah you need to remove the fuel screw and clean the passage. It is the most important and smallest one.
This is a good video. I hope between both your videos and mine, maybe people might start to understand how to do this on their own. But still I think people don't want to spend the type testing, changing a setting, testing, and so forth.
Thanks. Tuning can be a PITA, however with this circuit the answer is in the screw setting. Don't even have to ride it to determine if it is lean/rich.
Right, but novices I think lack the analytical mind we may have. This video builds on our previous information around the topic. Too bad it can't be better centralized. I have tried to do that on my website, and I might embed your video there.
@@thejunkman Yes and this is also assuming the carbs are in perfect shape. We all know that is rarely the case.
@@HTMR my vtx mixture screw was completely burned out and crudded up with rust and kept playing with the mixture not realizing till I dug deeper and once I cleaned it up it was much more responsive but now I’m dealing with slight hesitation during acceleration using barons set with 210 but they didn’t assign numeric value on pilot
great job thanks for making this. seems like whenever I need to do it I forget all this stuff.
I'm going to 3 turns air screw instead of 2 and 1size richer pilot jet. I've had a low speed cruise sneeze for years bugging me. THANKS 👍
I'm impressed with your knowledge and ability to teach. Taking the time to illustrate the theory is top notch stuff. I learned a lot, and really appreciate the time and effort you put into creating this video. I have an '86 Ninja ZX600R, purchased in '90, and it's always suffered from being too lean in the pilot circuit, and falling on it's face when the throttle is rolled on. I've had the carbs off and apart for cleaning, probably 3 times since purchase, (learning more as I go along in life) mostly due to leaving it sit unused for long enough that the fuel went bad in the carbs, but I didn't know about how jet sizing has an effect on mixture ratio, even though the pilot screw might be out enough that they idle is good. I've even synched them, and although there was a noticeable improvement, it's never be perfect. I'll be I could go a size or 2 up, and cure the issue, if any company is making jets still. Thanks again!
Check out jetsrus.com
I need a friend like this guy, I go to mechanics and they mess my bike up more then when I brought it, where's all the good semaritan mechanics in NY
You might have just saved my bike. Stay tuned! Thanks for taking the time. The most informative video on the subject that I've found. I can't wait to get home and try this.
Hahaha. Stay tuned. XD
Great video, very comprehensive. After removing the welch plugs on my '94 Kaw Voyager 1200, I discovered that two of the pilot screws were buried (zero turns out) and two were about 1.5 turns out. The plugs looked factory, so it's shocking that Kaw (or Keihin) would have messed up so badly. The guy I bought the bike from told me that it was originally sold in CA, so maybe that has something to do with it.
Just tuned up my pc800 and added a new air filter. 65k miles and she's running like a peach!
did you saw off he stops on the air/fuel limiters/?
Wow excellent Matthew, I have been mechanic on these for 55 years but some mixture screws didn't give me the proper response..you have taught me how to better decide the pilot jet configurations..Who says you cant teach an old dog new tricks..lol
Oh by the way..the carbs are already synchronized before this video?..Yes?
Liked and subscribed..thank you very much.
Peter
Yes carbs need to be synched before this procedure.
my xtz 750 SUPER TENERE IS 2KILINDRE PARALER AND if some working lite difrend about valve change not need maybe to one calbulator difrend turns???? for exaple one calbulator 3 turns and second 4 turns??? or allways need be 3+3???
Thank you very much for sharing that video, it was really informative and you helped me learn how to tune my pilot screws for my Kawasaki KLE500!
Watched tons of videos trying to figure out what i need to be looking for, for my carb and no one has explained it as clearly as you do. It all suddenly made sense.
Hay, HOW-TO. You made mentioned the popping sound in your audio. I know what it is. Someplace on that bike, the spark is jumping to the ground. Check the wires and boots.
I have a 2002 Honda shadow 750 ace running open cobra pipes 106&110 jets and 40s jet having trouble with popcorn exhaust help please
So I have a honda vfr750fk rc24 1989 I have carbs set to 4 and abit turns out runs lovely ticks over lovely I ride it atleast like 100miles and then pulled spark plugs out and showed a garage and they said it is running fine so I put them in let them have a go on my bike and they did a 3rd gear low rpm pull and it just picks up no flat spots or enything
Honda vfr750fk 1989 got stanles steel down pipes in to exhust can no baffles hight lift cams and tuned engine carbs are 4 and abit turns out but runs lovely spark plugs look good is it too much
They never have both the air screw and the fuel screw..... except when they do have both air & fuel screw, such as some early Suzuki GS models.
I am having a big trouble with my yzf 600r thundercat. He idles just okay when it is 2.5 turns out on 1 and 4 and 2 each on 2 and 3 from left. But i can smell it is really rich. It has stock jets. Doest have a a fuel screw it air screw. I thought it is leaning out when i turns it out🙄
After hearing it I can tell you that the popping on your audio is caused by rf interference from ignition system discharges effecting the electronics in your audio equipment.. Better audio curcuitry should have better shielding against it. Also possibly some form of suppression/filtering on your ignition system but I don't know if that can be done.
I have a Crf50. Hanging idle when throttle is let go. Needle isn’t sticking. Cleaned carb. No luck?
Why i have these screws on my 1999 Fi GSXR 750?
Why are these on a FI bike i dont get it.
I have a yamaha vstar 650 do you have any recommendations on jets sizes? And where to order them?
Already liked that video last year when I found it, looking for info about carb and rebuild and tuning but want to say thanks again since I completely rebuild both of my 96 1100 Virago carbs and currently having some issue to tune it well. I looked and dozens of videos but this one, I I look at again, clarified everything. You are very clear and really take the time to visually explain how the carb works. Thanks man! really nice work!
Hey man thanks a lot man I have Ben putting back a Yamaha 2006 r6 for 3 years now..it was throttling good and reving good..I had replace some head o rings n start the bike n it stop reving and a wile after it start to missing n he other thing as well the throttle body get tight..I take the plugs our clean them n free up the throttle body as well n check all wiers n all is good knick ..thanks a lot man n I'll try the 3 turns out n see what..keep what you do best by Charing your nalage..👍💯🔐
Thanks you MatthewMCrepair for making this videos and helping us out. I have one question. I have CBR 600, 1998 and it runs great on the streets but idle sometimes drops below normal point. Smell from the exhaust is really hard (gasoline) all of the pilots screws are 2.5 turns out (somebody before has messed with the carbs). I have taken the spark plugs out and found that number 1 and 2 are really black. 3 and 4 seems to be OK. Should I try to put number 1 and 2 let say 2 turns out and leave number 3 and 4 2.5? Or should I lean all 4 of them a bit and see how it runs? Thank you in advance and greetings from Croatia.
@@FourthWayRanch Tnx for the help. I will do that and see how it runs. Cheers
I have Mikuni VM26SS carbs and they have both fuel and air screws
Just thought I'd point that out to ya but great info u always give and keep up the good work 👍
Your a good teacher. Thank you....
Advance apology accepted.
hi my bike is running rich
.plugs are very suity at 3.5 turns out .this sets the fastest idle.would I go down one size with the pilot jet and main jet so it runs a little leaner 🤔
Absolute clinic. Insta-sub. Thank you 🫡
Xcllnt!
Will colortuning afterward be helpful?
I think that 3 turns out may only apply for CV carbs. The Amal and Mikuni need to be about 1.5 turns. I got an old GP Amal that has the air screw on that engine side. One side effect of running too lean a mixture is that the exhaust pipes can colour up, as happened with my Royal Enfield.
Yes, air screw is different, shoot for 1.5 out.
So if the aim is to get the smoothest fastest idle speed why did you lean it back down from 4 to 3 turns after pionting out that it had smoothed out at 4.i don't get that. Oh wait yes I hear you so once it smooths out it just stays like that does it and wastes extra fuel unless you trim it back to where it only just runs smooth.... Is that right?
you going to tell us how to adjust the idle screws are you going to tell us how to rebuild the entire f****** carburetor
You adjusted each carb the same amount.
Could some carbs need to be adjusted differently?
this helped me out a lot! I'm working on my pilot circuit on my yamaha radian, thanks for the informative video!
QUESTION, please (5 years later!) - How to know when your Pilot Fuel Screws are SEATED? When screwing in, the spring begins to add tension... but this is very soft and gradual. In theory you could twist that screw in a long way, using a lot of torque. SO- What is "SEATED" and how can you find this?
Keep going until it bottoms. Just use low torque to do so.
Dude I live in Chicago
Can you help me adjust the carbs in my magna
Hi you mention on the fuel screw, pilot jet, if it’s under one turn or maybe under two turns it’s too rich, but that doesn’t make sense as if it’s a fuel pilot screw, the more you turn it out the more fuel your adding, therefore surely if you turn it out for less than one turn, it’s too lean, and not too rich, it will only become richer the more you turn it out.
Is tbis lretry much a universal guide to most carbureted bikes?
"Carbs either has air or fuel pilots". Enter the Mikuni VM26SS on the first generation suzuki gs750
I know those exist, never seen or worked on one.
Привет, на сколько крутить pilot screw?
I have a 1980 yamaha xs1100 special and I have been having issues with setting my idle after rebuilding the carbs. this whole video gave me sooooo much help in understanding how this system works, I thought I had an air screw, turns out its a fuel screw. I'm an automotive tech and never messed with bikes before now and I appreciate how in depth you got explaining this.
I just wanted to post an update. Because of your video i now have a running and riding bike. Thank you soooooo so much
What did you do? I have a 80 XS Standard...
Best video about those screws :D Thank you
Two-stroke pilot valve plug
Fcr39 slant has both a pilot air screw and a pilot fuel screw
Oh, " and I also just made this number up" lol....regardless...I just took some of your advice! Very nicely done btw! I've ordered two Main jets size 125 , two Pilot jets size 42 and 2 shim for each Slide Needle for my 84 750 Shadow!
My problem is I have new mikuni rs36-d8-k carbs on my yamaha xj1100 amd jetted for the engine and per directions it says to turn them out ⅛ to ½ turns out max but it doesn't say from a light seat, fron a turn out, or anything in the directions. A light seat is something that is hard to determine because it is seated against a oring and each carb has a different feel and look when you look at each pilot jet screw with the carbs off so I've ordered a colortune to see where thigs are at. Your video is a great watch for sure and explains things perfectly.
ever used a colour tune on the fuel screws(bunsen blue at idle)
I had one years ago. Neat tool. Seeing is believing.
Hey, just a great explanation and I love rule of thumbs!! Can you tell me where can I get mukuni jets?
Can i get your opinion. I have gsx 750 f 2001 with slip on. I just got dynojet jetkit.On the basics it says that with slip on put 114 main jet,dynojets needle to pos 3 and all the pilot jets screws 3.5 turns out. Before this i had pilot screws in 2.5 in cyl 2 and 4 and on 1 and 4 3 turns out. Bike worked very nice but i thin it was little bit lean. I put the needle to pos 5 and now it work worst than the factory instructions. So should i put needle back to pos 3 and put 3.5 to pilot screw
First off, what is the problem? Then I can recommend a solution.
Thanks, great video. Each time you said you were turning 1/2 turn you actually turned a whole (1) turn. What's up there? I thought each carb should be adjusted individually. There may be variation in the carbs and engine that would require slight differences, don't you think?
1/2 turn is 180°
@@HTMR Yes it is. Watch 19:50 for example.
@@BasicPoke I am a bit late to the party lol. But the first one where he stalled it out he did a half turn out then a half turn back in. It looks like a full turn at first. The others were full turns I believe to reset things.
Hello! I would like to ask a question. If you might can help me. Bike is Yamaha YZF R6 2000. When I speed up with bike it rattles a lot and there’s black smoke coming out from the exhaust. Bike isn’t running perfectly when it’s in neutral. What might be the issue?
Sincerelly, Mika from Finland
At 1:35 you say that a carb will have either an air screw or pilot air screw, but never both... Mikuni VM fitted to Suzuki GS motorcycles from the mid 70s thru to the early 80s do.
I know they exist, just never worked on one in 30 years of wrenching. 99% of engines have one or the other.
Great explanation, really cleared up details
Vid is prob too old to get a responce but why does the service manual for my Yamaha YZF600R state to put the screws at 1 3/8 th turns ? Is that because it's a CA spec MC with smog rebreather ?
Yes, probably emissions etc.
Just bought a79 Honda 650 cb. Fun stuff.
That's the same one i've got. Gotta retune the carbs for the summer. How're you liking it?
Looking for Yamaha carburetor outboard motor
How to know if the pilot screw is fully closed??
Twin cards on a snowmobile then at the same principle or what
5 minutes 45 seconds in, you apologize for audio popping. Did your spark plugs have resistors in them? Does the spark plug number have an r on it? It can interviewer with your audio if it did not have a resistor.
I don't remember good point though.
When you say two turns out, do you mean two full turns??
Videos about Yamaha radian please
Hi i have a tgb target 525 . 503 cc engine. This use a mikuni carb BSR 33 (33MM DIAMETER) and i wanna ask what is the best jet combination to get max power and high rpm( 9.000...10.000rpm) .from the factory this came with .225 PILOT JET and 145 MAIN JET and at the moment is runing a ignitech cdi unit witch is programable and no rev limited. Thank you.
Hi, there i have a 1100 yamaha dragstar. Bike goes well, but everytime i stop the revs stay way upthere for a couple of seconds and then comes down back to idle mode. What could be the problem. Can anyone help please
Lean hanging idle. Adjust fuel mix screws.
Man.. I like that video. Did you equalize the carbs after that? Thanks.
hello!great work!i have a suzuki freewing xf 650 no exhust (im planninig to install)but open airbox..for sure going faster accelaration and sound but donst work perfecly..i was thinking for some jet kits tuning...please i need your help...thank you in advance
🙂
1997 vlx600, removed exhaust baffles and VERY restrictive airbox and filter, it became so lean it wouldn't come off idle, went from 40 to 45 on pilots and 115 to 155 on mains and raised needle height on clip position. Runs MUCH better but screw adjustment is 2.5 turns out on left carb and 3.5 -4 turns out on right! Any ideas on why such a difference?
thanks for the video. Ever experience a pilot screw that is stuck and won't come out. I got it broken loose and it backs partially out the bore but they just spings and doesn't fall out. Any ideas how to get it out?
Use a thumb tack and put pressure on it from the carb bore. Make sure the tack does not enlarge the orifice in carb body. Make sure threads are clean first.
@@HTMR thanks for the reply. I ended up soaking it in wd40 for a little and a few taps on carb body and out it came
I have a kawasaki zr7 750cc, carb is cleaned but I’m confused with the idle screw. This morning I had a ride, at traffic the rpm went up all of the sudden. What does that mean? My idle screw as at 2 turns. My carb is Keihin CVK. My jet size is 108 and screw is 38.
Hy, a sport exhaust can influence this settings?, and how?
I understand that this settings you presented are made with the genuine factory exhaust.
Please do explain this in a video.
Yes exhaust will require jetting changes.
@@HTMR how?
Absolutely fantastic video with the perfect amount of explanation to fully comprehend it!
On this radian with pods, did you change needle position or main jets? Or just pilot jets? I have an 86 radian I just put in a 6sigma jet kit which has 35 pilot. It idles good but as soon as I start to roll throttle it dies. Sounds like a bog but it dies so fast its hard to tell.
Yes, needles were shimmed (or clips moved) and larger mains. I can't remember the exact jetting though, it was a long time ago.
What if I only have one screw on my carb in the middle? And I drilled the plug out by the fuel bowl but there's nothing in the hole but another closed piece of metal?
Year make model?
Ok, i know these are motorcycles, but mikuni tm flatslide carbs on alot of snowmobiles have both fuel and air screws on the pilot circuit. I would love to know the procedure to tune those correctly.
Yeah I never came across a set of those.
Hello! Thanks for the detailed explanation! We are also in the the process of the tuning the fuel screws. Two questions if someone knows to help out 🙏
1. Before starting the process, where should be the idle revs configured? High, low or manufacturer suggested? Or something else?
2. What happens if the screws are in a location where it is probably impossible to tune them while the engine is running. Any tips and tricks?
P.S. The bike we are trying to tune is Honda Cbf 600, 2004. Thanks!
Hey bro. I have an ltz 400
Mikuni carb with
Main jet 140
Pilot 25
How many turns out my air fuel screw should be?
Also what level the needle clip should be on?
Thank you for this video and explaining this in depth. I have a 08 kawasaki teryx with the 750 and I don’t think the carbs have ever been set right for the riding terrain here in Oregon. So again thank you for taking the time to help
I have a question.. I bought a yamaha road star silverado 1600. Year 2000. It came with aftermarket exhaust, but only had regular filter and carburetor not adjusted. I was getting 46 mpg because the bike was running lean. Now I put a Dyno jet kit and K&N air filter. Now I'm getting 34 mpg. Is that normal? Also when I turn on the bike when cold I dont need choke and after warming up for a minute, I try to rev it quickly and feels like it chokes up, but if I wait for it to warm up for 3 minutes that won't happen. Is this all normal? It was backfiring when down shifting and deceleration. Now with this tune it doesn't do it which I like. It live in a desert environment at 3,000 ft of elevation. Thanks
Tim Heidecker explains carburetors lol seriously though, thank you!
So i got a 1995 honda VT700C for my son in law not running cleaned & bench sync carbs idles like a champ but if I put it on center stand runs great shifting through gears, issue comes when I go to ride it, it bogs down sputers chocks, you have to let off a little then slowly roll into the throttle every time you shift and even then it will sometimes bog out
I'm at a loss please help!!!
Just stumbled on you channel oh boy you just have answered a annoying problem with my 1990 ZXR750H2 (uk) my idle is slow to return to normal I do have mods I'm running micron headers to a SP stubby can with K&N filter im running 130 main jets high speed running is spot on. I do sometimes have a problem with the bike cutting out when hot at traffic lights your explanation of the pilot jets which I have set at manufacturing setting one and three quarters turned out looks like I need to turn them out further looks like mine is running lean and the fuel is evaporating before its pulled into the engine . I have uploaded a video of my bike to my channel me revving it and you can plainly hear the rpm slowly returning back to normal idle. Great video your never to old to learn thankyou so much for this video. Happy New Year and I hope 2021 is a good one 😎👍 ps you have a new sub
My 1978 Suzuki GS 1000 has a pilot fuel screw on the bottom of carbs and a pilot air screw on top of carbs.
I finally took the bike to a mechanic and had him do the valves and sync the carbs. Bike runs like new
I’m pretty sure that I could have done the valves myself and got it running sweet but it was well worth the money spent for piece of mind that it was done right. In fact the guy that did the work rides a Radian also. He said he was jealous at how nice my bike ran. I guess I got a good one.
How much did you soend
Your popping of the mic is from the bike and the spark plugs around idle. It was just the right frequency that could be heard via the mic!
BEST VIDEO ON UA-cam! QUESTIONS: I backed my idle screw all the way out on my vtwin 1100 vstar, and it still idles at around 800 RPM. When I lean it out idle goes down and when I richen it the idle goes up. But where it idles smooth and fast is too fast for the lowest idle screw setting. Also, note that when I close the AF screw all the way the bike still idles and will not stall even with the AF screw all the way in on the front cylinder. Also not that the rear cylinder AF screw has no real effect to any change I make to it, except the backfire pops, when I lean it out and less backfire pops when I richen it, but it does not have any real effect at idle. Only the front carb seems to affect idle. I bought this bike second hand. I think its time to ditch the carbs and buy another used set and start over?
Probably best to take the carbs apart and clean them. I have a video on that here: www.howtomotorcyclerepair.com/hondashadowcarbclean/
Our V-Star doing the same
Trying to see why it smells so rich and my tailpipe is burning cherry red hot after 10 mins
Well. . .I have looked and looked and this is so helpful, beats everything I've seen, so very well done and much appreciated. I could use a few minutes of private tutoring, are you available?
You mentioned audio popping 5min. 40sec. into the video. That would be due to the fact that your spark plugs do not have resistors in them. Without the resistors your spark plug wires become antennas that broadcast a radio wave.
Really want to thank you for all your very informative video's, I recently bought an 82 XS 650, and since then I have learned how to make noise out of money!
One of the best carburetor explanations I've seen. Plus actual rich/lean idle conditions and incremental adjustments on a running bike. Nicely done!