Volvo Penta

[IMP]

I have a '78 boat w/ a 91 gm 350 4bbl carb & Volvo Penta OD. The boat is 24' IMP deep V. It has replaced dist cap, button, points, wires, plugs. Took the boat out and was doing fine for first 20 minutes. We were at a plane w/ throttle all open, when it started making pinging noise and spitting back out of carb (backfiring.)The ping was not regular but sporatice, maybe lifters? It idles good and will below 3000 rpm, but once the pressure is put on the boat does this. Also it runs at about 180degrees, is this normal? I have a feeling it could be water in gas, timing out (but why would it run fine at low rpm?), Lifters out of adj't, Thermastat may be stuck. Any insight would be appreciated.

 

[akriverrat]

Re: Volvo Penta

water in fuel clogging filter/s or clogged filter/s or other constriction in fuel system or weak fuel pump. engine starving for fuel as demand increases with rpm. engine leans out causing pinging and lean pop out of carb. timing? 180 right on for closed cooling, high for raw water cooling. engine running lean will often run hotter.

 

[IMP]

Re: Volvo Penta

That sounds like it may be the case. I got boat they did not know when last changed water sep fuel filter. I'll also check carb filter. Is there a product that will really remove water from gas? Can I check if fuel pump is weak?-it is a manual pump.