Gents, I enjoyed reading your forum today and perhaps you can help me with a rather wierd problem.

The boat is a 30 f Gib Sea with a 11 hp one cylinder diesel of Renault Marine manufacture, 1978 year. Its is old one but until last season worked very well to get us around the lake.

The problem started last year when motoring, after some time the engine rpm would slow down from crusing speed to idel or worse, sometime dying out. In installed an outboard style bulb pump in the fuel line before the fuel filter, and a few pumps on this would get the engine running again. I assume air was getting in the line somewhere, so I took everything apart, cleaned the injecter, took apart the pump carefully and cleaned it out, changed all fuel liines, retightened everything, even took out the fuel tank pickup and put in a different tube, changed the fuel filter, bled the system, pumped up good pressure with the hand bulb, and lo and behold, the engine started ran for 20 minutes at a good speed, and then the problem reoccured. A few pumps on the hand bulb and the speed picked up. It is as if the fuel pump is not pulling in enough fuel to the motor to keep it running well at high rpm. It does not seem to be a problem with air in the system, as I bled it.

My question is what would cause this problem. I am beginning to think it is the fuel pump, It has a bosch label on it, but I have no idea or not if this kind of pump can be found again as the engine is almost as old as I am. taking it apart, everything looks ok as far as a novice mechanic can tell.

My second question would revolve around putting an electrice pump in the circuit after the fuel filter but before the engine, to keep a certain amount of pressure in the system when it is running. I noticed in your forum that a lot of people talk about this and I see it was recommended a facet 7psi pump. Would this likely solve my problem?

It is kind of bothersome motoring around the lake with one hand ont he tiller and the other on the fuel bulb.

Anyone have experience with these 30 year old Bosch one cylinder Renault Marine fuel pumps. Thanks, John Dunn

it seems to me you do need a new lift pump.and yes a 7 pund electric pump would fix this problem