If I atleast drain the fuel filter and clean the carb with some cleaner to get rid of the carbon build up the boat will run near perfect for close to an hour, then the problem comes back, and i have trouble getting it to hold 4000 rpms even. Temp about 170-175. Have changed oil now, fuel filter multiple times, fuel inlet filter, the line from the tank to the spin on filter, anti siphon valve, and cleaned the pickup in the tank, The fuel filter usually has some black particles in it when drained, but the tank did not appear to be dirty when I examined it. would like try to something else before i use it today, probably going to run some seafoam spray through the Carb and change the fuel filter again