Blaster noise!!!??

I recently got a 2000 Blaster with 30hrs on it. It sat - a mouse ate the air filter and the jerk I bought it from started it. He got cotton and other debris in the motor. So I cleaned it all out, removed the cylinder to be safe and crap was in the mains. So I don't have the crank removal tools etc. My Yami dealer split it put in new mains and I put rings in it - overall it was like new condition just contaminated. So anyway I broke it in and it cranks and sounds great. But here's the question when I zip quick in any given gear then let of the throttle to just maintain speed it sounds like something is smacking around in the motor?? This is the only time it sounds weird and maybe it is a characteristic of an air cooled teo stroke? But I just wanted to know what everyone elses sounds like?? :? :?:

[Tri-Z_Jim]

All blasters sound like that.If your unsure let the dealer hear it. Most air cooled 2 strokes ping like that at a certain rpm.

It almosts sounds like the piston clearence is huge! But I know it's fresh. It does sound like a ping though. Thanks!