hi there i just bought a klx 250r and it doesn't run. the guy i bought it from said that he thought the valves needed to be shimmed, and if this has to be done does anyone know how expensive this is to do.. The bike has spark, and its time is on. If you put your finger over the plug hole and kick it over it don't have enough compression to blow your finger off the hole. And tried putting oil in the cylinder and kicking it over didn't make no difference.. Does anyone know what my problem might be..