Check the plugs and the plug caps.They been known to go bad also.I use to run 17cc domes.I had 214lbs of compression.It didn't hurt anything.I use vp c 12 race fuel worked great.I had 300 main jets,but I'm in south at sea level,not quite where you are.The only thing about using 17's domes it will slow you down some on the top end.I later went to 19 cc domes to gain my top end back.The 17 domes help with throttle response,but you can put more timing in it for that instead using 17cc domes.