86 ProV 150 No Low End Power

[Craig P]

I have an '86 ProV 150 that has no low end power. Last time out I cruised along at 5200 rpm and the motor didn't miss a beat. Got to the water ski site and the boat struggled to pull a 160 pound slalom skier out of the water. Once on plane, will cruise along ok to 3500-4000 rpm, although a little eratic, very difficult to keep the engine at a specific rpm level. Checked timing at idle and full advance plus syncronization of magneto and carburetors. Also checked compression. The bank of cylinders where #1 resides all read about 90 psi with engine warmed up and throttle plates closed. Other three range from 100 to 115. Four plugs looked as if they were firing correctly, light brown and fairly dry (2 looked dark and oily). Engine has new water separator, external fuel filter and fuel pumps. Need to figure out why it's got no grunt on the low end. Any help would be appreciated.

[jb123]

you need to dissassemble carbs, clean and maybe rebuild if they havent been in the last few yrs.

you should do a strong decarbon to see if it helps compression balance out some.