Scuffing of cylinder bore to kill in the cylinder, so long as check to the piston, the following several reason is caused generally:

A. accumulate carbon on the top of piston and around ring is seriously ,using bad oil cause it mainly, such as using four stroke oil or diesel oil or two bad stroke oil.:

B. the piston exhaust is scuffing of cylinder bore ,air filter is not clean, the rubbish stops up the carburetor fuel device , little adjustment or put the oil little in the fuel, make entering the density of gas of the cylinder to reduce, it is insufficient to lubricate because paper cushion insulator leak gas, it cause to scuffing of cylinder bore easily on the high-temperature place.

C. The bottom entrance of piston is scuffing of cylinder bore, the reason is entering water, for instance using it in rain and snow day, water enter cylinder from air filter, then mix with the lubricate oil, make piston breathe lack lubricate oil, while turning round by high speed side, it will heat to causes scuffing of cylinder bore;

D. The piston entrance is scuffing of cylinder bore because of entering rubbish from air filter, main reason is :

1). forget to be put the air filter

2). Damage

3). Do not often clean