0
Some of you may remember my thread about rebuilding my KX125, detonation had the head & piston looking like they'd been a backstop for a shooting range. I rebuilt the thing with wiseco stuff and it runs great, probably twice the power as before. Powerband lofts the front end in almost every gear now.
The downside: Under load, 3rd gear and above, lower part of powerband it sounds like there's a lotto machine shuffling those stupid numbered ping pong balls in my engine. The bike will rev right past it, but i think it's safe to say the noise can be filed under the "bad things about to go catastrophically wrong" category.
My first thought was detonation, but 6 fingered man rode it and said it doesn’t sound like detonation. He knows his shit and I don’t, so I’m inclined to believe him. I’m still going to pull the head and have a look, but I’m thinking maybe something in the bottom end isn’t liking all the power the new top end gave it? Any suggestions, anything to look for? I was hesitant even posting with such a crappy description, but I don’t know how else to describe the sound. Aside from that the thing runs tops. Gobs of power, first kick every time (unless it falls over in the trailer and sits that way for god knows how long, then it needs Daniel to push-start it the first time and it goes right back to first kick).
I’m all ears to suggestions on anything I should check out/look for.
edit: Does it with Mobile 93, which I usually run, and Shell race fuel (guy @ stimilon said it was equivalent to C-12)