My bike is a 2003 RM250 and is still on the original piston and rings I believe.
I just bought it and have the original spares kit AND another full new piston and gasket set.
Do you think it would be a good idea to give her a change, Im guseeing it has done anout 25 hours work max. It starts very well and appears to have loads of power, but it is new to me.
Also the pistons have a yellow paint mark on the top, does this indicate what size piston from factory tollerance it is?
Final question, one piston is flat and the other is slightly domed, why, which is factory, the flat one?
Thanks