[headshrink]

I have my new-ish ebay engine in now (1.2K miles), and am working out the bugs. For the MOST part, everything seems good, or will be soon, but I was hearing a whine while under power today.

-The whine becomes hard to hear once the wind & pipe are too loud, so I didn't hear it on the freeway during yesterday's test.

-It sounds similar to a chain that is too tight, and SEEMS to match the speed of the bike, rather than engine.

-If anything, the chain is a tad on the loose side. The top part of the chain loop looks like it MIGHT rub the chain guard, HOWEVER I would think I would see the opposite result, since when it is under power, that part would pull tight.

-The wine can be heard all the way from when the wind quiets, to just before a stop, when the clutch is pulled in.

-I tried pulling in the clutch while riding, and it seems to go away, let out clutch, and it's back.

-I also tried revving it with the clutch in, while moving, but I need to do a few more runs before I can be sure about that test... got to work, had to go.

-I am using the SAME chain and 15T sprocket from my other engine. These parts have never given me a problem.

-Since the engine is practically still breaking in, I am using the cheapo walmart oil (no friction modifiers) for more frequent changes, before switching back to something nicer.

-The ONLY thing I did differently this time when removing the 14T and installing the 15T on the new engine, is use an impact wrench on the sprocket nut, as I suspect the breaker bar and torque wrench may have damaged the shaft and/or bearings on my old engine.

-I am having a little difficulty getting the clutch cable set, which I will address in a new thread if necessary, but thought I would mention it in case it may be relevant.

I'm stumped....

EDIT: Please read the update at post #14. A few of my origional assumptions where incorrect!