There are similar videos on this but yours is a more complete view with excellent explanations. Your time taken to respond to so many comments is appreciated by me and I'm sure many others. They are very helpful for understanding how the various elements work and affect each other. Thanks
I did some testing for a company when I was a kid. The new quality synth oils were just coming out at the time. I watched tests done with and without synth oil during break-in and it does make a difference. As you've stated, it's debatable. The compression numbers always favored non-synth. Only ran 15 mins at around 2000rpm to break in cam. Zinc is key, yes it's debatable. Very insightful video's. More informative than most. Too bad I just found them. 👍
Found two air leaks on our kx100. First was the gasket on top of the carb where the throttle cable runs through. Second was it was missing the copper gasket ring in the exhaust. Bought all new, replaced them all including the exhaust o rings and now it runs like a champ! Thanks for the video. Helpful!
Okay I will check that out. The fuel and starter fluid is good and even switched to a new plug. In more than 50 years I haven't seen something like this.
hi your videos are very informative, I recently bought a 93 yz 250, I replaced the cdi box after having spark issues, now it starts by the 3rd kick but after riding for a few days I noticed its sluggish and smokes more than my friends yz 250. were going to jett it tomorrow and fix exaust leaks. your videos on jeting 101 helped a lot , thanks, now we know the issue!
Great videos need to share this with the many I know who run way to rich of fuel oil mix as they believe it will prevent the engine from blowing, keep up the good work 😉
Base gasket is below reeds, airbox lid mods very common, but totally agree with the Ratio aspect. Whenever i break in i always move clip back to center to richen up to compensate!
My new yz250x recommends 30:1 after a break in of 15:1. But I run it at around 36:1-40:1 because I was fouling plugs. I’m using Yamalube because that’s what I can afford.
What do you have to say about a Honda CR 85 blowing oil out the end of the exhaust? I know nothing about bikes, and I bought one for my stepson from a kid from church. It runs excellent but I was concerned about the smoke and oil passing thru the exhaust.
Previous owner of my boat claimed to have blown up 2 engines so I am watching this. . . First step was pulling out all the heavy plywood and other extraneous junk.
You should add more hash tag type key words. Would help spread your videos. Very useful info, thanks again for the time you spend to help out the rookie banshee riders.
on my banshee some how it fluided out and got gas in with my crank and only running on 1 side what wood make it run on 1 its a new topend and i have spark pipe stay cold but smoke comes out thanks
just put in jd jet hit on my 03 ktm 250exc and i have black oil coming out of my exhaust. people have told me i should change my spark plug. im running 40:1
Great Video explained well both jetting and the air leak info points. I would not have thought exhaust as possible air leak. I think I have an exhaust air leak as I have noticed a little oil splurge on the expansion chamber of the exhaust pipe (so its leaking around exhaust mainifold). and once bike heats up (and things expand with heat) my idle starts to surge. (so its sucking air somewhere, and the exhaust manifold o rings are now suspect)
Okay I'm not sure Wat I did but the last time I was riding the first thing was spark plug cap came off second thing was it started having misfires now it doesn't get gas from carburetor to motor
pretty helpful, thanks for the info. i am trying to figure out the best ratios and oils for my 65cc moped engine that i just built. i was using full synthetic at 25/1 and upjetted. thinking about going to castor based around 30/1. plug looks good, but may need to upjet further. i'd rather be rich than lean. especially at wot around 10k rpms.
I have a 2004 cr85 I run 32:1 with Honda synthetic racing oil is that a good ratio and I have a oil leak coming out coming out of my clutch casing it's leaking pretty good when I'm riding is there any way I can stop this without getting a new clutch and case
Hello, I have a 2 stroke paramotor.....running synthetic oil 45:1 and high and low jets set to one turn out per all guidance I have received. Engine, however, consistently runs hotter than recommended based on the readings I get from my cylinder head wire meter. Any ideas what to check to get it to run cooler. Thanks
can someone help me my ktm 125 exc leaks or it doesnt leak but its spitting alot of oil from the muffler exhaust and then its dripping on the brake and the rim its full of oil and now my brakes doesn't work its dangerous i dont know what can have caused this but i recently did a engine rebuild and i put a new airfilter and i oiled the filter with filteroil but i think i put a little much cus its dripping from the airbox sometimes but i opened the airbox and its not full of oil or i dont see a problem in the airbox maybe i should take the filter of dunno pls help :D
I have just bought 1990 Johnosn 90hp. what should my ratio be also came with johnsom oil maybe old wahat do you think. thanks ib advance for your help.
We have a 9.9 mariner motor. When it is idling it appears to have oil come out if the exhaust ports. Is the gas/oil mix too rich? We use pennzoil 50-1 mix.
So I have a question in regards to the latter part of your video wrt oil and fuel ratios; I have a 98 1100zxi JetSki which I have recently converted from oil injection to premix (at 40:1) due to oil injection system failure which resulted in engine damage thus I've decided to eliminate that failure possibility going forward. So according to your theory, I should need to richen the jets to accommodate the oil now being mixed in the gas and metered through the jets so I get the same air-fuel ratio as I had originally. So any idea how much bigger the jets should be from the standard number (not even sure what the number on jets mean in terms of units (wire-gauge, caliber, diameter etc?)?
The oil injection/mix conversion isn’t a large enough change to worry about. When making multiple changes or large changes it should be a bigger factor. You’ll be fine keeping your current jets.
I picked up a Yamaha blaster for my daughter. It ran good for about a week and then wouldn’t start. First thing I checked was compression and it was at 100 psi and it is supposed to be from 140-160. I ordered new weisco piston and had a machine shop bore and hone the jug to match. The whole top end is new including gaskets and it still will not start and the compression is still at 100 psi. I can’t afford to take the bike to a mechanic can anyone please help I’m stumped?
Hi I have a 06 banshee I just rebuilt the top end myself. When I started it up after rebuild one cylinder doesn't run the same as the other one? The sequence is off when idling? Seems to run good but the idle is not real strong on one cylinder? Any ideas why? Thanks.
On my 250f when I Kickstart,some air flys out the intake side out air filter,any possibilitys i was thinking intake vale recut or-lapping needed psi compression is around 90,low..any ideas?
The piston sucks in exhaust (3:03)? Correct me if I'm wrong( wouldn't be the first time), but the piston is going down because of high cylinder pressure due to combustion. On the way down it is compressing the crankcase charge. As the exhaust and transfer ports are uncovered (opened) by the piston the pressurized crankcase charge enters the cylinder and forces the burnt mixture out the exhaust port. My understanding is that at no time is there negative pressure (vacuum) in the cylinder at the exhaust port. The only time there is a reversal of flow into the cylinder through the exhaust port is when the reflected pressure wave (when a tuned pipe is attached) returns to it's point of origin - the exhaust port. Bottom line -the only time anything enters the cylinder through the exhaust port is when a properly designed expansion chamber tuned pipe is fitted.
SparkysGarage The only negative pressure is in the crankcase, formed when the piston is on the upstroke, after the transfer ports are covered. That's what draws the intake mixture into the crankcase. Crankcase pressure is formed when the piston is on the downstroke, forcing the intake mixture through the transfer ports into the cylinder, and subsequently helping to scavenge the cylinder of the burnt gases. Your explanation of the effect of a richer oil/gas mixture can be somewhat misleading. You have to remember that the oil/gas to air ratio is close to 1:15. That means that @ 40:1 oil/gas, the oil occupies .17% of the volume of the cylinder. When the mixture is @ 20:1 oil/gas, the oil occupies .34% of the cylinder volume. That's a difference of .17%, less than 1/5 of 1%. Twice as much, yes, but pretty darn little in the grand scheme of things.
I have a question but first,Thanks for the information I found it to be helpful and I am always trying to further educate myself in anyway I can. So the question, I have a cr80 which I recently bought runs good and has a very powerful powerband which surprised me lol. Anyways it has an exhaust leak where the cylinder meets the pipe my main question is would this cause me to smell gas in my tailpipe? I cleaned the carb all is good there but I'm stumped any help would be great thanks!
FMFjake 89 Yes like the video says, that mixture is supposed to be pulled back into the combustion chamber and processed, but there may also be a vent tube from the gas tank to the muffler with an open back pressure valve.
I have a 1976 Yamaha DT400 2 stroke, i recently did a top end re build, i bored out the cylinder from an 85mm to 86mm since it was no longer a perfect circle. bike ran great before the top end change. now, when i kick it over. (it kicks over in 1-2 kicks) it will hardly idle and idle from 1000rpm and spike up to 7000rpm. and thoughts on why that is?
I have a 50cc scooter, about to install a bbk. Would an intake leak cause the rpms to rev very high all of a sudden? As if someone is holding the throttle a bit? This seems to of happened the last time I took my carb off.
Kind of a noob question but i have a rm125, its been ported, it has a fmf pipe (fatty) and a fmf shorty. I run amsoil 32:1 with gas mix 50/50 of 110octan and 93 octane. I noticed it runs better when theirs more 110 but im curiouse if i can hurt anything (motor wise) running to high of octane?
Compression ratio is the biggest factor which im not very familiar with. Most people "wing it" by guessing off of there compression PSI. A quick google search should give you an answer along with a solid compression test on a warm engine.
So I have a 49cc 2 stroke and I've noticed there is oil starting to show around the spark plug it still runs just fine however I'm not sure If I'm just not mixing the gas right or if I'm doing something wrong ? I'd like to not blow my motor if I could help it. any ideas?
I am buying a 97 banshee from a friend I trust that he has taken care of it based on the rest of all his toys that he personally works on he told me to mix 35:1 with quicksilver is that ok ? Do you suggest I get the banshee for fields and trails ?
I want to run my 89 Lt500r at 32:1. Running 20:1 because it says to, also it’s a lot of oil and smokes a lot. I haven’t had experience jetting and how to jet accordingly to said ratio. I’m running fully synthetic BelRay Si7. Any thought?
If you're running 20-1 it won't hurt your engine if you get the jetting right? IS that correct? My guess is that but I agree with you that a lean engine can cause detonation and blow your piston.
Hi I've got an air leak well a very big air leak from my exhaust where it connects to the cylinder head how would that change the performance ? Thank you
hey i have a 485 cheetah wth 35mm carbs im running a 170 main jet n its fine until i get into 6 gear then it fails hard but if i go 1 size higher jet it fails all over any ideas????
What would cause the engine to peek in rpm as soon as you start it I have an 2000 rm 250 I was riding for about 2 hrs then stoped for 10 min then started the bike and it instantly peek in rpm and would not shut off I had to pull the spark plug wire to kill the engine before it blew up and can't find any info about a problem like mine any info or guess would help
I have a question. I already been on all the forums. Bike will not start at all. Spark and compression is good. On the intake side I have gas leaking out of the carb. Very little suction. Im thinking theres an air leak on the stator side. How do I make sure that seal is good?
+Nani is not here either Carburator overflow is float height issue and/or clogging. Stator crank seal you can test with a motor pressure test, or just go ahead and replace the seal. Google this.
I have a 02 banshee an its seems to spit oil/gas out of where my pipes connect to the motor some body told me to just change the o rings an springs an that should fix it any idea what it sounds like to you I am running the fmf sst pipes an silencers
I was thinking of running 32:1 mixture using klotz super techniplate 2stroke racing synthetic oil thats blended with 20% benol racing castor oil. would that be a good mixture for a banshee thats bored out to a 353?
A friend brought a stihl hand held blower over thats been sitting. I checked the spark with a tester between the plug and plug wire. good spark checked compression 125 psi. without messing with the carb I put starting fluid in the cylinder and it would not even pop at all. Put a brand new plug in it and check it for spark was good still won't even try to start. I have never seen anything like this and have no answer. spark, fuel, and compression. starting fluid is good and have used it in other motors. any idea
+Marlen Sands Sometimes the stator pickup can get corroded or spacing can be off. It can make a spark but not one strong enough to ignite fuel. Also check to see that the flywheel key is in place. Make sure your fuel is fresh as well!
I just had the rod replaced yesterday on my KE100. I ran it on a 40:1 and was still smoking so bad. Also, had noticed black oil dripping out from the exhaust. Any suggestions?
The black liquid is hydrated soot,which is made from unburnt fuel-enriched mixture and unturned blow-by liquids. As long as it’s not depositing on the spark plug, it’s from normal operation and Youve got to check your choke. When it condenses on the spark plug, you have a fuel metering problem.
Could I put a 4stoke carburator on my Yamaha blaster 200 ,,I deleted the oil pumo and know using premix gas????I'll apriciate you answering to this cuestion
I have a 2005 kx125, the guy I bought it from didn't tell me what kind of gas/oil was in it. It was orange fuel though which was weird. But I leaned the bike because the bike was to rich with the gas he gave mean it. But usually I was gona run 32:1. But is it safe to do that. He might have been running full race gas and I jetted it to full race gas. What if I use Maxima racing oil with 92 pump gas which is the highest we get with out paying 90$ for VP.
Sounds to me like a coil/plug problem. When the machine heats up it might cause a short. Double check those areas. Almost make sure it is not overheating.
Thanks I've had a couple people tell me the coil,but some others also said the rings so I'll start with the coil. I just put fresh fluids in it so I don't think it's overheating.
Hi SG...very interesting....I have just started using a 50 year old British 2 stroke motor bike...the hand book say run at 24/1 petrol oil. I am using a synthetic oil in the gas at 40/1...and know I need to fit smaller jets as it will be running gas rich. I wonder have you any tips on what size jet I could aim to go down to...the old std main jet was a 180...but at higher RPM it lacked power...I now have a 160 main jet and its better but still not right...I have some smaller jet ready to go in...a 150/140/130. I fear going much small in case I seize the piston...have you any tips I can use to work out what size main jet to use. I have also dropped the needle one slot. Nick in the UK.
I got a banshee of some guy and he said he runs the oil 16oz to 4gal is that normal he would use yama lube I just by the yama lube and get the pre mix 4gal and mix it up with 4gals of gas is that ok to do ??
One question though. How do you tell how your engine was jetted? I have a 2003 Yamaha Blaster 200. The video refers to how the engine was jetted, and I would love an explanation as to what that means.
He has a video on explaining jetting :) definitely a very thorough video. Look that one up. It taught me a lot. I think it's called "jetting explained" or that's what you can type in..."SparkysGarage jetting explained."
I have the 80 cc motorized bike kit with an open pipe that a friend gave to me. its really loud so i put a stock pipe on it to cut the noise, but now the bike runs like shit but i put the other pipe back on it it runs good. what do i need to do to correct this problem??
Just recently rebuilt a lt250r and when we started it up it ran fine for a little bit and then it just went full throttle on it's own. Is this due to an air leak?
hello i using motul scooter power in 50:1. i want to try motul 800 in ratio 100:1. what do you think, will i need to adjust my main jet, because there will be more fuel and less oil?
hey i got 125 2 stroke with what i believe is a air leak its idle'in very high and idle ajust and air screw do nothing :( my pipe is in bad condition and has a big hole near 1inche in diameter and a long crack 4-6 inches..and there seems to be a oily residue where the carb attaches to the reeds think this could be my problem thanks :)
SparkysGarage so should buy a new pipe?? or can i get away with fixing the carb leak..also how do you recommand fixing the card-reed leak i was thinking duct tape or plumbers tape and maybe instand gasket
Well I need help I was just riding and I was down shifting and it just lost all power and the throttle wasn't doing anything any more and it wouldn't start back up I checked for spark and it's blue and it's not getting gas to the spark plug but there was gas in the bowl It's a 1995 rt100
Hey Sparky, I recently found out from the mechanics at the local Yamaha dealer that my bike had the proper jetting of 220 instead of 195 stock, what does that mean? Which oil/gas ratio would you recommend I run and do they sell oil made to be mixed at that ratio? Previous owners ran 32:1.
There are similar videos on this but yours is a more complete view with excellent explanations. Your time taken to respond to so many comments is appreciated by me and I'm sure many others. They are very helpful for understanding how the various elements work and affect each other. Thanks
David Kirkpatrick thank you for the awesome comment!
I did some testing for a company when I was a kid. The new quality synth oils were just coming out at the time. I watched tests done with and without synth oil during break-in and it does make a difference. As you've stated, it's debatable. The compression numbers always favored non-synth. Only ran 15 mins at around 2000rpm to break in cam. Zinc is key, yes it's debatable. Very insightful video's. More informative than most. Too bad I just found them. 👍
Thanks for the video. This video taught me a lot about two stroke engine basics. Please keep up the good work!
Found two air leaks on our kx100. First was the gasket on top of the carb where the throttle cable runs through. Second was it was missing the copper gasket ring in the exhaust. Bought all new, replaced them all including the exhaust o rings and now it runs like a champ! Thanks for the video. Helpful!
Glad the vid helped! Please share it!
Okay I will check that out. The fuel and starter fluid is good and even switched to a new plug. In more than 50 years I haven't seen something like this.
hi your videos are very informative, I recently bought a 93 yz 250, I replaced the cdi box after having spark issues, now it starts by the 3rd kick but after riding for a few days I noticed its sluggish and smokes more than my friends yz 250. were going to jett it tomorrow and fix exaust leaks. your videos on jeting 101 helped a lot , thanks, now we know the issue!
superscaryeti Awesome! Glad they helped :)
Great videos need to share this with the many I know who run way to rich of fuel oil mix as they believe it will prevent the engine from blowing, keep up the good work 😉
Thanks a ton for the comment. Wish word would get out about this info.
Thank s for taking the time to make this video.
Thanks man. Helpful! I'm checked for air leaks now... it's on a scooter, et2 italjet. White smoke.......new carb.......
Base gasket is below reeds, airbox lid mods very common, but totally agree with the Ratio aspect. Whenever i break in i always move clip back to center to richen up to compensate!
thanks,you helped a lot and you make it easy to understand
Glad it helped!
My new yz250x recommends 30:1 after a break in of 15:1. But I run it at around 36:1-40:1 because I was fouling plugs. I’m using Yamalube because that’s what I can afford.
Thank you, very informative video! I did a few videos diagnosing this issue on my. 2 stroke motorcycle, you’ve done a wonderful job!
Thank you!
-words- video worth of gold
For sure. I don't have a ATV I have a yamaha dtr125 but the video is still relevant thanks for sharing
What do you have to say about a Honda CR 85 blowing oil out the end of the exhaust? I know nothing about bikes, and I bought one for my stepson from a kid from church. It runs excellent but I was concerned about the smoke and oil passing thru the exhaust.
I have the same issue! But with my 49cc 4 stroke motorized bike
Previous owner of my boat claimed to have blown up 2 engines so I am watching this. . . First step was pulling out all the heavy plywood and other extraneous junk.
THANKS FOR THE HELP MAN!!
Happy to help!
@@SparkysGarage If you have a exhaust leak by engine will this cause the bike to run lean??
Very informative. 👍 I plan on going from 22:1 to 32:1 on my next full up on my 66cc.
You should add more hash tag type key words. Would help spread your videos. Very useful info, thanks again for the time you spend to help out the rookie banshee riders.
Glad the vid helps!
on my banshee some how it fluided out and got gas in with my crank and only running on 1 side what wood make it run on 1 its a new topend and i have spark pipe stay cold but smoke comes out thanks
just put in jd jet hit on my 03 ktm 250exc and i have black oil coming out of my exhaust. people have told me i should change my spark plug. im running 40:1
Everyone has their own opinion and I can completely understand that. Definitely get that exhaust patched up! Ride hard bro! :)
Great Video explained well both jetting and the air leak info points.
I would not have thought exhaust as possible air leak.
I think I have an exhaust air leak as I have noticed a little oil splurge on the expansion chamber of the exhaust pipe (so its leaking around exhaust mainifold). and once bike heats up (and things expand with heat) my idle starts to surge. (so its sucking air somewhere, and the exhaust manifold o rings are now suspect)
Nice detective work :) Definitely sounds like you found the problem!
Okay I'm not sure Wat I did but the last time I was riding the first thing was spark plug cap came off second thing was it started having misfires now it doesn't get gas from carburetor to motor
pretty helpful, thanks for the info. i am trying to figure out the best ratios and oils for my 65cc moped engine that i just built. i was using full synthetic at 25/1 and upjetted. thinking about going to castor based around 30/1. plug looks good, but may need to upjet further. i'd rather be rich than lean. especially at wot around 10k rpms.
I have a 2004 cr85 I run 32:1 with Honda synthetic racing oil is that a good ratio and I have a oil leak coming out coming out of my clutch casing it's leaking pretty good when I'm riding is there any way I can stop this without getting a new clutch and case
had air leaks out of my dt 125LC bike with smash it with a hammer to try and stop the problem .
Hello, I have a 2 stroke paramotor.....running synthetic oil 45:1 and high and low jets set to one turn out per all guidance I have received. Engine, however, consistently runs hotter than recommended based on the readings I get from my cylinder head wire meter. Any ideas what to check to get it to run cooler. Thanks
Hi I have a 2 stroke 50 cc super Moto and it starts first kick but it lacks power and is blowing white smoke what could this be ? Thanks
can someone help me my ktm 125 exc leaks or it doesnt leak but its spitting alot of oil from the muffler exhaust and then its dripping on the brake and the rim its full of oil and now my brakes doesn't work its dangerous i dont know what can have caused this but i recently did a engine rebuild and i put a new airfilter and i oiled the filter with filteroil but i think i put a little much cus its dripping from the airbox sometimes but i opened the airbox and its not full of oil or i dont see a problem in the airbox maybe i should take the filter of dunno pls help :D
Thanks man. Wish it had more views, its probably one of the most important videos I've made so far.
I have just bought 1990 Johnosn 90hp. what should my ratio be also came with johnsom oil maybe old wahat do you think. thanks ib advance for your help.
So I got a 1979 kx 80 and I run 32:1 so idk if that's a low. Or what should I be mixing it to.
We have a 9.9 mariner motor. When it is idling it appears to have oil come out if the exhaust ports. Is the gas/oil mix too rich? We use pennzoil 50-1 mix.
So I have a question in regards to the latter part of your video wrt oil and fuel ratios; I have a 98 1100zxi JetSki which I have recently converted from oil injection to premix (at 40:1) due to oil injection system failure which resulted in engine damage thus I've decided to eliminate that failure possibility going forward. So according to your theory, I should need to richen the jets to accommodate the oil now being mixed in the gas and metered through the jets so I get the same air-fuel ratio as I had originally. So any idea how much bigger the jets should be from the standard number (not even sure what the number on jets mean in terms of units (wire-gauge, caliber, diameter etc?)?
The oil injection/mix conversion isn’t a large enough change to worry about. When making multiple changes or large changes it should be a bigger factor. You’ll be fine keeping your current jets.
One of the best.
it colui Also be that the powerband valves are clogged. My 2 stroke had that problem and as soon as I rode it in powerband it didn't leak
I picked up a Yamaha blaster for my daughter. It ran good for about a week and then wouldn’t start. First thing I checked was compression and it was at 100 psi and it is supposed to be from 140-160. I ordered new weisco piston and had a machine shop bore and hone the jug to match. The whole top end is new including gaskets and it still will not start and the compression is still at 100 psi. I can’t afford to take the bike to a mechanic can anyone please help I’m stumped?
I did a troubleshooting video. Search for it on my channel.
Hi I have a 06 banshee I just rebuilt the top end myself. When I started it up after rebuild one cylinder doesn't run the same as the other one? The sequence is off when idling? Seems to run good but the idle is not real strong on one cylinder? Any ideas why?
Thanks.
Old Toys Check out my troubleshooting vid, there are a lot of possibilities.
Worst one is where the carb bolts on the intake
On my 250f when I Kickstart,some air flys out the intake side out air filter,any possibilitys i was thinking intake vale recut or-lapping needed psi compression is around 90,low..any ideas?
Thats some low compression, might be blow by and time for a rebuild
If you ride in wet conditions keep your air box. Go with a K&N or UNI filter.
The piston sucks in exhaust (3:03)? Correct me if I'm wrong( wouldn't be the first time), but the piston is going down because of high cylinder pressure due to combustion. On the way down it is compressing the crankcase charge. As the exhaust and transfer ports are uncovered (opened) by the piston the pressurized crankcase charge enters the cylinder and forces the burnt mixture out the exhaust port. My understanding is that at no time is there negative pressure (vacuum) in the cylinder at the exhaust port. The only time there is a reversal of flow into the cylinder through the exhaust port is when the reflected pressure wave (when a tuned pipe is attached) returns to it's point of origin - the exhaust port.
Bottom line -the only time anything enters the cylinder through the exhaust port is when a properly designed expansion chamber tuned pipe is fitted.
There are plenty of videos on how youtube vids on how 2 stroke engines work. Check them out. There is definitely negative pressure in the cylinder.
SparkysGarage The only negative pressure is in the crankcase, formed when the piston is on the upstroke, after the transfer ports are covered. That's what draws the intake mixture into the crankcase. Crankcase pressure is formed when the piston is on the downstroke, forcing the intake mixture through the transfer ports into the cylinder, and subsequently helping to scavenge the cylinder of the burnt gases.
Your explanation of the effect of a richer oil/gas mixture can be somewhat misleading. You have to remember that the oil/gas to air ratio is close to 1:15. That means that @ 40:1 oil/gas, the oil occupies .17% of the volume of the cylinder. When the mixture is @ 20:1 oil/gas, the oil occupies .34% of the cylinder volume. That's a difference of .17%, less than 1/5 of 1%. Twice as much, yes, but pretty darn little in the grand scheme of things.
Could a leaking pipe at the cylinder cause engine damage due to a lean condition or crack an exhaust bridge with the cold air rushing back in?
Yes, absolutely
I have a question but first,Thanks for the information I found it to be helpful and I am always trying to further educate myself in anyway I can. So the question, I have a cr80 which I recently bought runs good and has a very powerful powerband which surprised me lol. Anyways it has an exhaust leak where the cylinder meets the pipe my main question is would this cause me to smell gas in my tailpipe? I cleaned the carb all is good there but I'm stumped any help would be great thanks!
FMFjake 89
Yes like the video says, that mixture is supposed to be pulled back into the combustion chamber and processed, but there may also be a vent tube from the gas tank to the muffler with an open back pressure valve.
I have a 1976 Yamaha DT400 2 stroke, i recently did a top end re build, i bored out the cylinder from an 85mm to 86mm since it was no longer a perfect circle. bike ran great before the top end change. now, when i kick it over. (it kicks over in 1-2 kicks) it will hardly idle and idle from 1000rpm and spike up to 7000rpm. and thoughts on why that is?
***** Sounds like classic air leak symptoms. Check that all bolts and nuts are installed and torqued properly.
Should I jet up or down if I decrease the amount of oil added to the fuel?
Thank you bro. Great help
Glad it helped man! Give it a like and share it plz.
32:1 or 36:1 is ok to run with yamalube as long as the quad is jetted correctly.
Awesome video there sparky keep it up. I run 38:1 with Carlube 2stroke motorcycle oil pretty good stuff.
I have a 50cc scooter, about to install a bbk. Would an intake leak cause the rpms to rev very high all of a sudden? As if someone is holding the throttle a bit? This seems to of happened the last time I took my carb off.
Yes it definitely could. Check for leaks and make sure the throttle is responding as it should
Kind of a noob question but i have a rm125, its been ported, it has a fmf pipe (fatty) and a fmf shorty. I run amsoil 32:1 with gas mix 50/50 of 110octan and 93 octane. I noticed it runs better when theirs more 110 but im curiouse if i can hurt anything (motor wise) running to high of octane?
Compression ratio is the biggest factor which im not very familiar with. Most people "wing it" by guessing off of there compression PSI. A quick google search should give you an answer along with a solid compression test on a warm engine.
So I have a 49cc 2 stroke and I've noticed there is oil starting to show around the spark plug it still runs just fine however I'm not sure If I'm just not mixing the gas right or if I'm doing something wrong ? I'd like to not blow my motor if I could help it. any ideas?
Ever figure out why? & a fix..
I am buying a 97 banshee from a friend I trust that he has taken care of it based on the rest of all his toys that he personally works on he told me to mix 35:1 with quicksilver is that ok ? Do you suggest I get the banshee for fields and trails ?
The important part is the jetting. Not so much the fuel mix ratio. I have never heard of a 35:1 mix.
on my yz125 there is no rubber seal on where the silencer connects to the pipe, does that cause loss of power?, or cause the bike o go lean
not at all. It's supposed to be there.
I want to run my 89 Lt500r at 32:1. Running 20:1 because it says to, also it’s a lot of oil and smokes a lot. I haven’t had experience jetting and how to jet accordingly to said ratio. I’m running fully synthetic BelRay Si7. Any thought?
Run it at 32:1 or even 36:1 and youll be fine, any quality fully synthetic oil can run those numbers without issue
If you're running 20-1 it won't hurt your engine if you get the jetting right? IS that correct? My guess is that but I agree with you that a lean engine can cause detonation and blow your piston.
Hi I've got an air leak well a very big air leak from my exhaust where it connects to the cylinder head how would that change the performance ? Thank you
If its a 2 stroke and sucks in enough air it'll run you lean and blow your engine. Get a gasket in there.
Welcome brother. Ride safe!
hey i have a 485 cheetah wth 35mm carbs im running a 170 main jet n its fine until i get into 6 gear then it fails hard but if i go 1 size higher jet it fails all over any ideas????
What would cause the engine to peek in rpm as soon as you start it I have an 2000 rm 250 I was riding for about 2 hrs then stoped for 10 min then started the bike and it instantly peek in rpm and would not shut off I had to pull the spark plug wire to kill the engine before it blew up and can't find any info about a problem like mine any info or guess would help
almost always an air leak
I have a question. I already been on all the forums. Bike will not start at all. Spark and compression is good. On the intake side I have gas leaking out of the carb. Very little suction. Im thinking theres an air leak on the stator side. How do I make sure that seal is good?
+Nani is not here either Carburator overflow is float height issue and/or clogging.
Stator crank seal you can test with a motor pressure test, or just go ahead and replace the seal.
Google this.
I have a 02 banshee an its seems to spit oil/gas out of where my pipes connect to the motor some body told me to just change the o rings an springs an that should fix it any idea what it sounds like to you I am running the fmf sst pipes an silencers
I was thinking of running 32:1 mixture using klotz super techniplate 2stroke racing synthetic oil thats blended with 20% benol racing castor oil. would that be a good mixture for a banshee thats bored out to a 353?
***** I would stick with one oil and one fuel for mixing.
A friend brought a stihl hand held blower over thats been sitting. I checked the spark with a tester between the plug and plug wire. good spark checked compression 125 psi. without messing with the carb I put starting fluid in the cylinder and it would not even pop at all. Put a brand new plug in it and check it for spark was good still won't even try to start. I have never seen anything like this and have no answer. spark, fuel, and compression. starting fluid is good and have used it in other motors. any idea
+Marlen Sands Sometimes the stator pickup can get corroded or spacing can be off. It can make a spark but not one strong enough to ignite fuel. Also check to see that the flywheel key is in place. Make sure your fuel is fresh as well!
I just had the rod replaced yesterday on my KE100. I ran it on a 40:1 and was still smoking so bad. Also, had noticed black oil dripping out from the exhaust. Any suggestions?
The black liquid is hydrated soot,which is made from unburnt fuel-enriched mixture and unturned blow-by liquids. As long as it’s not depositing on the spark plug, it’s from normal operation and Youve got to check your choke. When it condenses on the spark plug, you have a fuel metering problem.
i have a honda cr250r 2 stroke. there is oil coming out from under my spark plug. why is it doing that?
Yes. Good question same thing with my 1998 yz 125
I have
coolhead
64mm wiseco piston
Toomey 5 pipe
k&n filter
v force 3 reed
boost bottle
I need to jetting the carb
how I mix the oil 32:1 ?
Yea it's a 32:1 my bad one more question I bought the banshee today only one pipe is smoking I feel exhaust good still just no smoke on left side?????
I did an exhaust smoking vid, check it out.
Thank you for this one!! 🙏
Any time!
Correct. You must jet for the mix.
I am running the red line synthetic oil two-stroke racing oil 40 to 1 ratio would be OK you think?
Should work great!
Also it has a K&N air filter but no air box lid
deffinatly gonna favorite this video!!
All the name brand fully synthetic oils are top notch
Could I put a 4stoke carburator on my Yamaha blaster 200 ,,I deleted the oil pumo and know using premix gas????I'll apriciate you answering to this cuestion
Yes, you can
@@SparkysGarage THANKS SPARKY
I have a 2005 kx125, the guy I bought it from didn't tell me what kind of gas/oil was in it. It was orange fuel though which was weird. But I leaned the bike because the bike was to rich with the gas he gave mean it. But usually I was gona run 32:1. But is it safe to do that. He might have been running full race gas and I jetted it to full race gas. What if I use Maxima racing oil with 92 pump gas which is the highest we get with out paying 90$ for VP.
Hey I've got a 05 125 sx and it starts fine cold but it will only bump start once it gets warmed up. Do you know what I could do to fix this?
Sounds to me like a coil/plug problem. When the machine heats up it might cause a short. Double check those areas. Almost make sure it is not overheating.
Thanks I've had a couple people tell me the coil,but some others also said the rings so I'll start with the coil. I just put fresh fluids in it so I don't think it's overheating.
Hi SG...very interesting....I have just started using a 50 year old British 2 stroke motor bike...the hand book say run at 24/1 petrol oil.
I am using a synthetic oil in the gas at 40/1...and know I need to fit smaller jets as it will be running gas rich.
I wonder have you any tips on what size jet I could aim to go down to...the old std main jet was a 180...but at higher RPM it lacked power...I now have a 160 main jet and its better but still not right...I have some smaller jet ready to go in...a 150/140/130.
I fear going much small in case I seize the piston...have you any tips I can use to work out what size main jet to use.
I have also dropped the needle one slot.
Nick in the UK.
check out my plug chop videos. Remember if its mean its lean
I got a banshee of some guy and he said he runs the oil 16oz to 4gal is that normal he would use yama lube I just by the yama lube and get the pre mix 4gal and mix it up with 4gals of gas is that ok to do ??
One question though. How do you tell how your engine was jetted? I have a 2003 Yamaha Blaster 200. The video refers to how the engine was jetted, and I would love an explanation as to what that means.
He has a video on explaining jetting :) definitely a very thorough video. Look that one up. It taught me a lot. I think it's called "jetting explained" or that's what you can type in..."SparkysGarage jetting explained."
Unfortunately I am not familiar with that machine so I can't give you numbers. However throw me some info anyways. What are you running?
I have the 80 cc motorized bike kit with an open pipe that a friend gave to me. its really loud so i put a stock pipe on it to cut the noise, but now the bike runs like shit but i put the other pipe back on it it runs good. what do i need to do to correct this problem??
Sounds like you are due for a rejet. Stock pipes stop a lot of flow. Less air means you need less fuel, sounds like its time for a smaller jet.
Marty Cordova what is the open pipe i have a mototrized kit to
Just recently rebuilt a lt250r and when we started it up it ran fine for a little bit and then it just went full throttle on it's own. Is this due to an air leak?
Sounds like it to me.
Very welcome
hello
i using motul scooter power in 50:1.
i want to try motul 800 in ratio 100:1.
what do you think, will i need to adjust my main jet, because there will be more fuel and less oil?
Adjustment would definitely be needed.
SparkysGarage thx for quick reply!
i using 130 (metric) main jet, how many point it can be reduced, what do you think?
I would change it 2 sizes to start
what do u think about klotz oil that's is a good oil?
What do you call the little hose/seal thing that connects the headpipe to the silencer? Mine is starting to wear out.
+bushwood4568 Exhaust clamp
Purchase some thick heater hose as it's cheap and easy.
hey i got 125 2 stroke with what i believe is a air leak its idle'in very high and idle ajust and air screw do nothing :( my pipe is in bad condition and has a big hole near 1inche in diameter and a long crack 4-6 inches..and there seems to be a oily residue where the carb attaches to the reeds think this could be my problem thanks :)
That is definitely your problem. I wouldn't recommend riding it again until the problem is fixed.
SparkysGarage
so should buy a new pipe?? or can i get away with fixing the carb leak..also how do you recommand fixing the card-reed leak i was thinking duct tape or plumbers tape and maybe instand gasket
Pictures or video of the leak would help.
SparkysGarage
check your inbox :)
Is it ok if i run it on premium gas (93 octane)?
Yousif Jaba Yes
Is it better to use premium?
There is a lot of factors
One gallon is 128 ounces so 4 gallons is = to 512oz 512/16oz=32 so he is running 32:1
i run yamalube so whats better more oil or more gas?
i juss bought a 2000 banshee and the guys said he mixes it 40 to 1 is that too lean?
No, 40:1 is what I run.
Well I need help I was just riding and I was down shifting and it just lost all power and the throttle wasn't doing anything any more and it wouldn't start back up I checked for spark and it's blue and it's not getting gas to the spark plug but there was gas in the bowl
It's a 1995 rt100
+Maddogmoon moon Sounds like your main jet is clogged. Are you sure you didn't lose compression?
+SparkysGarage im gonna check that tomorrow but it still has compression but I was reading up about it and it might be a piston ring
+Maddogmoon moon it's also getting way to much oil its oil injected
+Maddogmoon moon Blaster?
+SparkysGarage blaster?
It definitely is nowhere close. There is a guy that put a banshee engine in a 450 though I believe. Heavily modified frame though.
Hey Sparky, I recently found out from the mechanics at the local Yamaha dealer that my bike had the proper jetting of 220 instead of 195 stock, what does that mean? Which oil/gas ratio would you recommend I run and do they sell oil made to be mixed at that ratio? Previous owners ran 32:1.
+Quinton King 220 is richer than 195. I run 40:1 with fully synthetic oil.
I run 24:1 using yamalube in my banshee will that hurt the motor ?
It will not "hurt" your motor, but you won't get the best performance out of it either.
Awesome! :)
Whats your take on castrol oil ?