went to start my bike this weekend and it had zilcho compression. it tried to start but just popped once and died. so i noticed a little coolant coming out of the head. btw this motor uses 2 rubber o-rings. i have probably no more than 10 hours on the new piston which looks great would it be a good idea to put a new one in with that amount of time or just ring it and put new o-rings in.