Hi there. I recently pulled my sherco apart as there was a sharp knocking from the top of the cylinder which i am led to believe is piston slap. After rebuilding the bike with a new piston, rod, bearings, gaskets and seals, the noise is still present. I have now removed the cylinder to find 2 deep scores on the cylinder wall and i also find there is movement in the piston where there shouldnt be!

If anybody knows of piston liners or other remedies, any information or help would be much appreciated.

The actual liner is a hard plated surface. It can be redone and fitted to the piston if the piston is still good.

Not sure why you would suddenly develop the deep grooves?

Anyway, dependant upon where you are located, you may even be able to get an exchange set already done at less cost than new.