iv got a 96 yamaha kodiak 400 4x4 i recently rebuilded the top end of the engine a couple months ago and it has been running great since but recently it has started smokeing alot after it has warmed up but still runs like the day i rebuilt it . when i first start it up it does not smoke after a minute or two it starts a little white smoke nothing unusual then after 5-10 minutes it starts to smoke alot and you definetly can smell the oil . and every time i use the atv it has to toped off with oil what could this be ? i havent been beating it up since the top end rebuild i use it only when it snows just to plow my small driveway thanks for any help !

 

anybody ???? please help!!!!!!!!!!!!

 

Could be many things. Here are just a few.

#1 Could be too much clearance between the valve and guide. Was that checked? Were new valves used? New seals will cut up very quickly if there is too much clearance.

#2 You could have broken a ring.

#3 You could have gotten the piston to wall clearance too loose.

#4 The finish on the wall could be wrong.

I would do a leakdown and see what you get. A compression won't tell you much, but it is better than nothing.

One more thing. If it is smoking at a study throttle, it will be the rings or ring seal. If it is smoking when you shut off the throttle and then get back on it, it will more than likely be a guide problem seal problem.

 

yeah i never checked the valve to guide clearence wasnt sure how to do that so im not ruleing that out . i did check the gap on the rings and that was perfect in spec. and i did remove the glaze from the cylinder wall ... the last time when i rebuilt the top end my rings were so bad it compleatly stoped running the gap on the rings was huge more than .100 thousanths but i checked the cylinder for being out of round and it was right still at 83mm like at factory specs and it was smokeing about the same before rebuilding the top end so mabye a ring broke but im hopeing its valve guide related.

 

Hey bud i got the same problom here wat did u find out let me no

 

Did you remember the Oring between the case and the jug? Since the motor doesn't smoke than quit I don't think it is the valve seals unless they are totally gone. Did you rework the head when you rebuilt it this time or last? Did you put the rings on upside down?

 

 

Yes the piston rings