"also if its really lumpy I`ll slow it down some to 2100, 2200, which still shows me 20 mph +- 2, also when I might get some"
Typically boost builds at about 1800-1900 rpm and gets larger above those rpm. Dependent upon the exact boat, gearing and props it is possible to have a hump area where there is insufficient boost and the fuel load can be too large. Adding EGT gages so you can read the temps and make sure you are in the safe zone is not really expensive at all.
I know that adding pyro and boost gages to my past 3 boats have taught me a lot about the engines, allowed me to consume less fuel and kept the engines safe from poor operating parameters. There was no way to read these engine loads or conditions with the existing temp, oil and rpm gage.
