Fuel problems

[2mate]

Hi there,
I've got a 1991 40hp 4cylinder oil injected mercury which is giving problems. I've just installed a new fuel pump kit and impeller due to it breaking down on me a few months back. The engine only starts when carb cleaner is sprayed in. This tells me the problem is fuel related. I have removed the outlet hose from the pump and span the engine over but no fuel comes out?
Any ideas?

 

[Texasmark]

Re: Fuel problems

If you have a disconnect connector at your engine for your fuel line, disconnect the connector. Take something like a popsickle stick, cut down to half width with somewhat of a point, or any plastic or non metallic device that will depress the sealing piston in the supply side of the connector.

Depress the spring loaded sealing ball bearing and while doing so, pump the squeeze bulb. The results just cut your solution in half.

If you got a good supply of clean fuel out the connector the supply to the engine is OK. If not chase problems in the tank, pickup filter, bulb or fuel line.

Assuming the above test was ok, then you have a fuel delivery problem through the engine. Possible causes are clogged fuel filter, fuel pump diaphragm ruptured, clogged fuel line, float on the carb stuck shut, or internal fuel contamination of the carbs.

Since you said what you said, then after you check the fuel inlet....Test 1 above do the rest of what I said with the fuel line to the carb disconnected where you can monitor it.

Shouldn't take much for you to find your smoking gun.

Mark

 

[quicktach]

Re: Fuel problems

You may want to go back over your installation of the new fuel pump kit and impeller to make sure you did it all right. If so, it's then a matter of going between the kit and the fuel tank ...looking to anything that will prevent fuel delivery. Tank vent unplugged
and open ?
Keep us posted!