Thanks everyone for the answers about my motor; just to let everyone know what I've found out. The motor didn't have correct spark, (powerpak/electronic brain) VRO was only working about 50% of the time, which was in turn fouling out the plugs, and one piston was worn copletely out. So I'm having it completely rebuilt. It will be bored at 40 over and everything will be factory new. It will also increase my HP to about 200!!
For anyone with one of these motors, if your tach starts acting up you need to check your VRO; and if you have a "cough/cutout at idle check the powerpak for correct spark.
I had this boat at 6 different marine dealers and NOT ONE found these things out. Spent about $4500 (enough to have rebuilt the motor) befor I had a friend look at it with his tools (for nothing) and with the spark device you could watch the spark not working, with the tach jumping all over the place that showed the VRO problem; and just by pulling off the heads EVEN a non-mechanic like myself could see the wornout cylinder!!!! Hope these things can help someonr else avoid these problems.