Hello all!, My name is Matt, and i'm new to this forum. Forgive me my english, i'm a french canadian (quebec). I have trouble with my 1997 Yamaha Wolverine 350. I just put in a new 0.020" wiseco piston, have the cylinder bored by a reputable machine shop. Now, on startup and until it warmed, it smoke blue and smell burnt oil. I rode it about an hour, slowly, with short burst of throttle, but the smoke is still present. Once it warmed, there is no more visible smoke. I had the valves seals replaced and valves guide checked, with no luck. I have check the rings, they were properly installed. The clearance between piston and cylinder is 0.0025" that seems good. What can be wrong with it? Any idea? Thanks

 

it could just need a little time to let the rings break in, just kinda take it easy dont run it hard and overtime it should go away after the top end has broke in.

 

I have rebuilt other engine and never noticed smoke like this. The first time I started it, It wasn't smoking. I have rode it around the house very easy, 15 min at time, let it cool all night between ride. I'm going to ride it and see if it become better or worst. Any other idea are welcome Thanks

 

When the rings were installed, the oil wiper ring could have been installed in the wrong order, or upside down.