Where did you get your domes? Did you have them cut? What is your squish at? I ran a gas motor at 195 psi for two seasons...I did back out the plugs on a couple occasions, but the few times, something was not right(lean jetting, and had oring sealing problem causing a coolant leak). And as mentioned, definately don't up the timing till you get it straightened out. Oh, and one other question. Are you running a stock cdi?