Great advice guys.

I definitely think it is lack of rpm, and probably a carb tuning issue. I think this issue was here before I rebuilt the engine (has probably less than 100 hrs on it and runs very smooth throughout the rpm ramge) and also dealt with some bad wiring of the ignition system.

The carb hasn't been looked at in over 10 years and I'm sure I screwed around with the metering block and mixture screws when I was having bad performance before the engine was rebuilt. It has symptoms of the secondaries not opening because you don't hear that deep tone that you typically would from other cars of boats I've been in whenyou go from partial to WOT...I'll try the paperclip test.

I did throw a vacuum gauge on the engine in tbe driveway. At idle it's pulling around 15-17" and based on research that seems to lead towards a healthy motor but potentially also a timing issue for base. Any thoughts?