gear oil on 2 stroke

yamaha125cc

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Hi i just bought a 2001 yz 125 and do any of you know what kind of gear/bottom end oil i should put in. And also when i mix the gas what should the ratio be. The guy who had it before me said 35:1. I dont know if that right for what kinda of riding i will be doing.

I will be trail riding most of the time but every now and then i will go ride my friends track. Just say il be doing trail riding. Thanks
 

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Slamnek

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Nice bike! I have always mixed my bikes 50:1 with amsoil dominator and amsoil motorcycle 10/40 in the clutch. Good oil makes everything last longer. 35:1 seems too rich too me try 40:1 and check your plug color and go from there.
 

synergycycle

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i would sagest running motul fully senthetic and mix it at 40:1. also for crank case oil just use like a 10w30 or 40.
 

slomo

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gear case is 10/40 and make sure it is motorcycle specific or you'll take your clutches out in 10 minutes,or use a 1040 oil that does not say energy conserving as it does not have the friction modifiers that allow the clutches to slip,40:1 for fuel
 

j_w10

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Yup i always ran 40:1 with ams sythetic and 10-40 in the clutch never had a problem mixed the bike up oncne at 30:1 with a cheaper oil and kept fouling the plug.
 

ktm 13-44

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Wow, you guys ALL have it wrong. Go read the manual for this bike. 32:1 is standard yamaha 2-stroke.

it's worth your time and money to go buy the manual for that bike. You'll learn so much just reading specs.

have you googled any of these questions?

The reason you're fouling plugs has nothing to do with how you mix your oil. it's the fuel that fouls plugs. I've fouled plugs in my KTM and im running 60:1.

the manual is going to tell you to mix Yamalube's 2T at 32:1. that stuff is great, and its nice and cheap. That oil you get at canadian tire is crap, and its meant for weed eaters.

you just bought a 10 year old bike, whats the point of running fully synthetic oils? that stuff is too expensive for the tiny difference its going to make to your bike.

fun bike man! good luck!
 

synergycycle

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Wow, you guys ALL have it wrong. Go read the manual for this bike. 32:1 is standard yamaha 2-stroke.

it's worth your time and money to go buy the manual for that bike. You'll learn so much just reading specs.

have you googled any of these questions?

The reason you're fouling plugs has nothing to do with how you mix your oil. it's the fuel that fouls plugs. I've fouled plugs in my KTM and im running 60:1.

the manual is going to tell you to mix Yamalube's 2T at 32:1. that stuff is great, and its nice and cheap. That oil you get at canadian tire is crap, and its meant for weed eaters.

you just bought a 10 year old bike, whats the point of running fully synthetic oils? that stuff is too expensive for the tiny difference its going to make to your bike.

fun bike man! good luck!

if you run a high performance synthetic oil you can run a bit leaner. it lubercates better, you do have a point though. a manual is super nice to have. and if you have proper jetting and your using proper oil you should never foul plugs.
 

Slamnek

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All the manufactures say to run 32:1 because its safe. Mine runs awesome at 40:1 with full FMF exhaust and stock jetting. My plug color is dark brown which tells me its still in a safe zone. I have also mixed richer with a cheap oil and my bike ran like chit.
 

j_w10

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have to agree with slamnec it wasnt the stuff for weed eaters that i was using it was a shell full synthetic that i bought and my jetting was fine cause i never changed it just changed the oil and ran the rest of the year on the new plug. fyi my bikes are always jetted according to the manual till the mods start.
 

yamaha125cc

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Thanks guys! Helps alot. I read up and it dose say 32:1. i think i might run a bit lean. 35:1 beczuse that what the guy always put in there and it was a full tank and when i went out last it ran great.

I also was hitting so jumps and on this one table is really sandy ( the hole pit is really soft sand) so put this mat on the take off and it made a big difference. Hit the mat went alot fast then i was intending had it tapped almost back flip ditch the bike slamd on the ground. Only damage broke rear fender. FRom dealer 88 dallors of a site 23 plus shipping.
 

TheLonelyIsland

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Thanks guys! Helps alot. I read up and it dose say 32:1. i think i might run a bit lean. 35:1 beczuse that what the guy always put in there and it was a full tank and when i went out last it ran great.

I also was hitting so jumps and on this one table is really sandy ( the hole pit is really soft sand) so put this mat on the take off and it made a big difference. Hit the mat went alot fast then i was intending had it tapped almost back flip ditch the bike slamd on the ground. Only damage broke rear fender. FRom dealer 88 dallors of a site 23 plus shipping.

that sucks dude! did it just crack or sbnap right off?
 

yamaha125cc

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snapped right of and broke in 4 place the sticker kit is holding it toghter. Il show a picture when i get around to take a picture
 

Modman

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The reason you're fouling plugs has nothing to do with how you mix your oil. it's the fuel that fouls plugs. I've fouled plugs in my KTM and im running 60:1.

False - trying running your bike at 15:1 with perfect jetting - see what happens. :d 60:1 - that's lean IMO. Oil is cheap protection, 40:1 is as lean as I go. I know what the new oils say on the bottles, that's an emissions thing, but it doesn't mean you should go that lean. Oil is there to protect the motor, you don't want it to burn all away, there will be nothing left to protect the motor. You need some ash on things like the piston dome and combustion chamber to help cool these parts.

A plug fouls for one of two reasons - the plug is too cold, or the plug gap is bridged by foreign debris (oil, aluminum, etc). If your plug is fouled and it's not debris, then the plug is too cold to burn an effective spark from center to ground electrode, whether it was cooled by excess fuel (jetting too rich) or excess oil in the fuel (mix ratio too rich). You can jump a heat range to get better burning of the oil off the electrodes, but you don't want your plug to blister, if it does, it's too hot of a plug.
 
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Actually, you can get more horsepower out of a two-stroke engine with enough extra oil in the gas, because the oil provides a better ring seal and, therefore, more compression. People think that gas burns more efficiently with less oil, and therefore you get more performance. It almost makes sense if you look at that one statement alone.

The seal of the piston is critical. If you remove the lubricants from the gas, the viscosity of the mixture becomes lighter and more prone to vaporization. With a lean mixture, there is less oil to seal the rings. The sealing of the rings has more to do with the performance of the engine than the possibility of having better-burning gas with an ultra-lean gas/oil ratio.
 
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False - trying running your bike at 15:1 with perfect jetting - see what happens. :d 60:1 - that's lean IMO. Oil is cheap protection, 40:1 is as lean as I go. I know what the new oils say on the bottles, that's an emissions thing, but it doesn't mean you should go that lean. Oil is there to protect the motor, you don't want it to burn all away, there will be nothing left to protect the motor. You need some ash on things like the piston dome and combustion chamber to help cool these parts.

A plug fouls for one of two reasons - the plug is too cold, or the plug gap is bridged by foreign debris (oil, aluminum, etc). If your plug is fouled and it's not debris, then the plug is too cold to burn an effective spark from center to ground electrode, whether it was cooled by excess fuel (jetting too rich) or excess oil in the fuel (mix ratio too rich). You can jump a heat range to get better burning of the oil off the electrodes, but you don't want your plug to blister, if it does, it's too hot of a plug.


Are you fouling plugs? Many people will tell you all sorts of band-aid fixes, from running less oil, to running a hotter plug. Both are incorrect fixes for plug fouling. It's all in the jetting.

The only way to know what jetting changes you will need is by trial-and-error. No one can give you jetting specs, because every bike is different, every rider has a different style, and jetting is totally weather dependent. Unless the person telling you what jets to use is riding an identical bike, on the exact same track, at the same time, his recommendations are meaningless.
 

yamaha125cc

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Actually, you can get more horsepower out of a two-stroke engine with enough extra oil in the gas, because the oil provides a better ring seal and, therefore, more compression. People think that gas burns more efficiently with less oil, and therefore you get more performance. It almost makes sense if you look at that one statement alone.

The seal of the piston is critical. If you remove the lubricants from the gas, the viscosity of the mixture becomes lighter and more prone to vaporization. With a lean mixture, there is less oil to seal the rings. The sealing of the rings has more to do with the performance of the engine than the possibility of having better-burning gas with an ultra-lean gas/oil ratio.

Thanks alot, that helps.
 

Modman

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Are you fouling plugs? Many people will tell you all sorts of band-aid fixes, from running less oil, to running a hotter plug. Both are incorrect fixes for plug fouling. It's all in the jetting.

The only way to know what jetting changes you will need is by trial-and-error. No one can give you jetting specs, because every bike is different, every rider has a different style, and jetting is totally weather dependent. Unless the person telling you what jets to use is riding an identical bike, on the exact same track, at the same time, his recommendations are meaningless.

No, I've never fouled a plug. I do change them every season though, and I also use a couple tricks like indexing and a ground electrode split to get better flame kernel exposure.

It's not all in the jetting and running a hotter plug is not a band aid fix, it's the reason they make hotter or colder plugs, to maximize power out of your motor be achieving perfect combustion temperature. Yes you need to be close with your jetting, and then you can tweak it with the plug and achieve a better result in the end. This is not understood by many people. Plug heat range and jetting are two very different motor issues, one can exist without the other. Jetting is related to the air/fuel ratio and at what temp that mixture burns in the cylinder. Plug range temp relates to ignition temp, vapourization temp of the fuel you are using, plug temp, how much carbon is burnt off the plug, etc, etc. Jetting has more to do with altitude and air density than just the weather. Jetting is only a portion of the equation, if you think that you can make a bike run perfect on 15:1 fuel/oil with custom jetting, you can go ahead and try - I'll be riding while you try and figure out why your bike won't run. Too much oil in the fuel and not a hot enough plug will result in incomplete mixture burn (vapourization) and cause too much deposition on the plug, resulting in fouling of the plug. So you can cut back the oil (if you are at 40:1 already - bad idea IMO), or you can jet leaner or you can run a slightly hotter plug and jet slightly fatter for a margin of safety.

I jet lean and run one hotter range plug, never, ever fouled a plug, I mix at 32:1 and my pyro's run about 1320 on a long steady pull. I can gain or lose 50 degrees just by changing the plug heat range, once it is fine tuned with jetting. My oil ratio never changes, but I could foul my bike out with too much oil and a cold plug if I wanted to. :)
 

vic

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Hi i just bought a 2001 yz 125 and do any of you know what kind of gear/bottom end oil i should put in. And also when i mix the gas what should the ratio be. The guy who had it before me said 35:1. I dont know if that right for what kinda of riding i will be doing.

I will be trail riding most of the time but every now and then i will go ride my friends track. Just say il be doing trail riding. Thanks

My 2003 honda runs 32:1 as per manual spec never any issue. Check you plug lettering to make sure your running the right one. May solve your fouling. Get the manual or call your dealer for info.
 

yamaha125cc

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My 2003 honda runs 32:1 as per manual spec never any issue. Check you plug lettering to make sure your running the right one. May solve your fouling. Get the manual or call your dealer for info.

Thanks nice sled you have there what is it m8 vic
 
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