i am selling my blaster....i had sum guy come to look at it, and he asked me to start it up... so when it was idleing, he said he heard a very slight knocking in the cylinder, whenever i reved it ...it got faster, i told him it was the piston goin up and down, ive had this sound since i bought the machine in 2002, i am 99% sure its the piston... my question is, do u have a slight knocking sound in ure cylinder? and when u rev it...does it go faster?

 

maybe its a loose pipe or part around the engine. I doubt its piston slap.

-Nick

 

I'll bet that it is where the exhaust meets the motor. there is a flange that connects the exhaust to the motor that might be loose.

 

Ive had that too since i left the dealer w/ mine. It also does it when i ride in 6th gear a while and let off the gas completely. Its like a pinging or knocking. Ive ignored it. Runs fine.