I pulled the side cover to work on the clutch. When I put it back, it leaked a little oil because the gasket was damaged from pulling it of. I wanted to test ride it so I overfilled the oil to compensate for the leak while I rode it. It smoked terribly when I started it. I could see oil in the power valve, so I guessed that leaked into it from around the gear. I drained out the oil, refilled with the proper amount and rode it for about a half hour putting in a few ounces every 5 mins to keep the level correct. After 5-10 minutes, it cleared up and ran fine. Today I filled it up (900ml) and fired it up. It ran fine until I put it on a milk crate (running) then started smoking again.

When I had the cover off the power valve gear came off with it. There was no seal on its shaft. Should there be? Maybe it fell off when I removed the case and I didn’t see it.

Has anyone else had a similar problem?

 

The power valve parts visible through the window are a spring with the washer on top. A leg off the washer is bent 90 degrees toward the engine, with the spring legs going on either side of the bent leg, I believe that bent tab goes to the left, about 9 o'clock, then you put in a small bolt to hold it together. My memory isn't all there, but that sounds right, at least on my '89 LT-R. I hear the power valve is a big boost at low end, and medioum at middle throttle. Anyone gone to MotionPro twist throttle on an LT? My wife loves hers on the little EX, it was an easy install, so I'm thinking about it.

 

You may have caused too much crank pressure by over filling it with oil which could have caused the clutch side crank seal to become damaged. What color is the smoke and what does it smell like?

 

The smoke was blueish gray and smelled like buring oil. I think I may have overfilled it again the 2nd time becuase I asumed that all the oil leaked out and it was empty. I have it fixed now with the correct gasket. I filled it exactly 900ml after I put it back together and it has not started smoking again.