White smoke

[SurferDude]

Does anyone know why my 06 yz 125 2 stroke makes so much white smoke all the time? Is it normal or should i fix something?

[OLHILLBILLY]

It's either jetted pig rich, or you have a bad right side crank seal.

[SurferDude]

By jetted rich you mean too much oil on gas?

[OLHILLBILLY]

By jetted rich you mean too much oil on gas?

Lol, no. "Jetted too rich" means the pilot and/or main jets are too large. Pre-mix ratio (how much oil you're mixing in your gas) has very little to nothing to do with it. First thing you need to do is pull the carburetor off, give it a thorough cleaning, see what jets are in it, and then post all this here.. https://www.thumpertalk.com/forum/79-yamaha-2-stroke/  Edit: Nevermind, I see a mod has done that part for you..  ?

The other possibility for a cloud of smoke is a leaking crank seal allowing it to suck in and burn gear case oil.

Edited July 13, 2015 by OLHILLBILLY

[SurferDude]

Ok, the bike is old but hasnt been used, nothing has been changed on it but i did open the right side to change the shift stopper, ill check if I tightened it properly

[BillDirt1]

Ok, the bike is old but hasnt been used, nothing has been changed on it but i did open the right side to change the shift stopper, ill check if I tightened it properly

 

Hasn't been used...good chance it's the right crank seal like said above.  Might as well replace both bearings & seals while in there.

[War_IS_the_Answer]

Crank seal, gasket?

[YZDOC]

Exactly what bearing would be replaced with the seal? Seal sits behind the primary gear only way to get to the crank bearing is the split the case. I don't think that needs to be done. It's probably just a seal and you can replace the outer gasket if you want to their not usually bad

[SurferDude]

Is this the seals you are talking about except that a 2006 instead of the 99?

https://www.thumpertalk.com/topic/1026348-yz125-crank-seal-replacement/

Crank seals/ oil seals

[YZDOC]

Yep, that kit will do them all. Except you will get the one for 2006, not 98-2000 or 2001-2004. Haha

[SurferDude]

So is there one specific seal i nerd to change or all of them?

[YZDOC]

Yah, you could just do the crank. I'd replace them all. You can without complete engine removal.

[YZDOC]

Oh, make sure your crank bearings are not the reason for seal failure. If that's the case of your smoke problem.

[mrjata]

Just for gits and shiggles, pull the plug and see if there is any rust or moisture droplets.  I am thinking head gasket/ (o rings).  To me, blue or dark smoke is oil, white is water.  Just my $.02  I wonder if ATF is white or blue smoke???

[Wyatt]

X2 on water. Check your coolant level if you see a lot of white smoke.

[numroe]

ATF burns to make a light grey smoke. Some might call it white.

[SurferDude]

Greyish I guess

[numroe]

Looks a lot like transmission oil smoke! Therefore right side crank seal. Does it smell Ike coolant or not?

[SurferDude]

Not really and coolant is full

[YZDOC]

Are you sure the jetting is correct for area and temp?