There is something imbedded in the top of the piston pull the spark plug and look for damage. Also try and take a mirror and look down the plug hole.

 

Wow, KD, I've never heard a 2-stroke sound like that before. (Course....I don't own one newer than 1979!) Thanks for the vid/audio!

 

thanks so much for taking the time to make a vid!!!!! sounds almost exactly the same ! but i believe my bike did not come with the kips system. not sure if that matters or not. i will try and send a vid as well, first i will take everybody's advice ! what a great site thanks everybody !!

 

so i took the top end off and if i stick my finger down the cylnder and leave the piston half way down i can move the piston side to side and i can hear it "knock" against the cylnder wall somewhat similar to the knocking sound when the bike is running !! piston Slap???!! What next??

 

Apparently a top end re build is in order.

 

ok piston is majorly scored so i will replace !! cylnder looks fine though!! what would cause the scoring and if the piston is scored why wouldn't the cylnder be as well ?? also any one know the proper jets for 4000 ft altitude??? im in Alberta Canada.

 

Welcome to KF dude!

 

Who knows, all sorts of stuff happens in the chamber. Grab yourself a Wiseco piston and ring kit if you can. Even if you take the bike into the shop to get the work done you won't get killed on labor from an honest shop on a 2 stroke. Good luck and let us know how it turns out.

Mike