I have 1959 Johnson Seahorse 5.5 HP that I have been having trouble starting and it sometimes dies out once I do get it running, so I did a compression test. I did the compression test on a cold engine (It wasn't running beforehand) and it was 55 psi in both cylinders after about 4 pulls. They are identical readings, but it seems really low to me. I recently replaced the head gasket, cleaned the cylinder heads and checked the cylinders for scoring, hot spots, etc. and it all looked good. I also took a look at the coils through the peep hole, both are badly cracked, so could that be the better reason for poor starting? Do I need to do a complete rebuild of pistons, rings, etc. to have good compression or is 55psi good enough for this engine?