| I agree on the vent, but you might get lucky. If the piston is not scored badly, sanding it and new rings might be enough. In my younger days, I rode a National enduro in the Mojave desert. One of the guys on my minute had an aftermarket tank without a good venting system. He put a main jet in the vent line to keep it from spitting out gas. That motorcycle seized more than once before he told me about the jet in the vent line. |