I have an 86 LTF230, it blue smokes quite badly when you start up the quad. Actually, it takes about 5 seconds after it starts before it blue smokes, then it gradually clears up and does not smoke untill you stop the engine again. The longer it sits, the worse it smokes. I just had the cylinder off of the quad, I can still see the crosshatch marks on the cylinder, rings are not stuck, put new valve stem seals in it, adjusted the valves, reseated the valves, new gaskets everywhere. It acts like a valve seal is leaking, but they are new??

 

Are the valves new too, Sounds like a valve seal problem. I had the same problem with mine and i rebuilt the top end completly.

 

i had one that i serviced that the tranny had too much oil in it and it overflowed into the airbox out the vent tube and it smoked terribly cuz it was pulling the oil through the carb and burning it. but if its not that i would say its the oil rings. they allow oil through till they get fully expanded then stops smoking when they seal up the bottom of the piston. if you changed the valve seals then these two can be your only options.

 

Looks like the exhaust valve is newer, something at one time came loose in the engine because there are a few good dings in the cylinder head, either it didnt mark up the cylinder or it has been replaced, the piston has no dings in it either, it possibly dropped an exhaust valve, which is why it looks new. The old valve stem seals were loose over the valves, these new ones are tight. Oh well, I have have to say it is rust proofing the exhaust system, at least it doesnt always smoke.

 

one of my sons friends quad smoked alot after it sat awhile turns out that his dad serviced the air filter with motor oil didn't use sticky filter oil. as it sat oil would drip down thru carb and into motor.

 

I have a tired old 1986 LTF230G that started smoking real bad on a cold start with the choke on. It would die immediately the choke was off but start reving up with it on and I had to ride the choke like a throttle till it warmed up by which time it had filled the yard with smoke.
After it warmed up,the choke was taken off and it ran fine with just a hint of smoke, which I put down to its age.

Did a bit of head scratching and reading up in here - then it dawned on me - the last person to ride it had pulled the 'cold start' control open !
(I never needed to use it, so never noticed it)

I pushed the button in, tried a cold start and the old girl has given up smoking.
Easiest fix I have ever had - but it had me going there for a while!