I got a used motor for my Blaster off ebay a few months ago from a reputable seller. I rode it a few times and it was making this wierd rattling noise in the top end, so I tore it down and took the cylinder and piston over to the Yamaha shop near me where the mechainic measured it and told me it was worn out, must be the problem right?
I go home and take out my feeler gauge and check all the crank tolerances and shake it to check for vertical movement. Nothing is out of the ordinary. So I send the cylinder out to be bored at Lakes Motorsports on ebay.
They bored it 20 over and sent me a complete Wiseco rebuild kit with a pro lite piston. I got it back today cleaned it good, took my time, read all my manuals. Put it all back together, torqued it all down, bled the injector pump and fired it up. It idles fine and sounds good other then that damn rattling. It's still doing it. If I put a screwdriver up to the head with my ear on it I can hear a definite noise right at the top. Exactly as before. There is no evidence of the old piston coming into contact with the head and I'm sure this one isn't. The only other noise I ever heard from it was a spark knock at very high RPM (like when doing a powerslide in second or third).
Is this just the engine running and that's how it sounds or is there something else I need to look into? I just don't want the engine to blow apart and become totally useless like the old engine that came on it was.
I'd really appreciate some input, thanks.
I go home and take out my feeler gauge and check all the crank tolerances and shake it to check for vertical movement. Nothing is out of the ordinary. So I send the cylinder out to be bored at Lakes Motorsports on ebay.
They bored it 20 over and sent me a complete Wiseco rebuild kit with a pro lite piston. I got it back today cleaned it good, took my time, read all my manuals. Put it all back together, torqued it all down, bled the injector pump and fired it up. It idles fine and sounds good other then that damn rattling. It's still doing it. If I put a screwdriver up to the head with my ear on it I can hear a definite noise right at the top. Exactly as before. There is no evidence of the old piston coming into contact with the head and I'm sure this one isn't. The only other noise I ever heard from it was a spark knock at very high RPM (like when doing a powerslide in second or third).
Is this just the engine running and that's how it sounds or is there something else I need to look into? I just don't want the engine to blow apart and become totally useless like the old engine that came on it was.
I'd really appreciate some input, thanks.
