02 660 Engine death/rebuild? pics...
Well, this tear down didn't exactly go as I planned...first a little background...
I bought a cheap Raptor from a friend needing money (Strike 1). Wouldn't start when I bought it and it generally looked kinda ratty (Strike 2). Carb rebuilds, new battery and L&A One-way. Start the bastard and poof! Blue Smoke (Strike 3)
Whatever. I'll rag the hell out of it (success), swap the piston/rings out, and tada! No more smoke!
First, the piston, rings, and cylinder are in great shape. No evidence of blow by from what I can tell, the bore is smooth as a babies ass, and the piston skirt is also in great shape.
Now, my concerns are the cylinder head and crank shaft. The crank looks like it got super hot (no oil, it burned it all off...) and probably killed the bearings. The crank does still spin by hand smoothly and freely. The cylinder head, however, pretty much looks like crap. The left exhaust valve is super cruddy, and the cam shaft bore has been chewed up and pulverized a bit.
On with the pictures...
Piston. Lots of carbon/oil crap on top. My first guess is valve stem seals.
Note the exhaust valve closest to the camera. Super nasty.
Chewed up cam journal...
Same journal, but showing the "lip" made...The camshaft somehow made it out of all of this ok.
Overheated, under lubricated crank...
Now...what are my best options? I don't want a 123234323342cc Raptor. This is a toy. Something to cruise with the lady friend. Relax compared to the dirtbike. The only thing I plan to "upgrade" at this point is the piston. Other than that, stock is best... Should I replace the crank? keep it oiled and wait for it to explode later? What do OEM cranks go for? I need a new cylinder. That's a non-negotiable. Prices?
Give me your thoughts, comments, suggestions on getting out of this without breaking the bank! Thanks!
2006 CRF250R / 2002 Raptor 660 / 2005 Blaster 200
Last edited by CRF Esteban; 03-11-2010 at 09:06 PM.