1985 Force 50 HP - lost power

[seaspray65]

Hi. I am all new to this...Out on the boat over the weekend. While coming in I was at full throttle and all of a sudden it was like I went from full speed to about 1/4 speed. There was no loud bang or anything..It didn't sound like it was struggling.. It just basically decided to limp home. When this happned, I put it in neutral and then I started to throttle forward no problem but again, at full throttle it moved like it was just starting out. I checked the gas lines, I checked the Raycor filter no water. Bulb was hard. I don't think it was a gas starvation problem. Checked the spark plugs...they looked normal for a whole season. I replaced them the beginning of the year. I'm baffled. Where to begin to figure out whats up??? Thank you for your time.

 

[inquizito]

Re: 1985 Force 50 HP - lost power

something in the fuel delivery system maybe - a screw holding in one of the fuel pump valves had loosened and torn through the fuel pump diaphragm, causing this symptom to occur with my 1987 Force 50 507F7C. Might also want to check the fuel screen outside the pump housing or any in-line filter.

I have recently experienced far less power at high throttle - and had overheated recently, and have been informed this could be a ruptured head gasket - in the shop getting the dreaded diagnosis now. And of course, the tank might no be properly ventilated - we all forget this sometimes - unscrew the valve, and if it has been closed, unscrew the cap to depressurize, leaving the air valve open afterward.

Everyone on here always says it has to be 1) fuel supply 2) spark 3) air 4) compression - or something closely similar when troubleshooting troubles. . .