Frustrated...

[polar21]

I just got back in town from the Bahamas, and like most people, I took the rest of the week off of work and wanted to take the boat out. I cranked the boat up at the house and ran it for aprox. 5 minutes and saw that all was well. I get to the boat launch and fire the boat up and proceed to start filling the ballast bags and the motor stops running. Weird.... I stop filling the ballast bags and the try to crank the motor and it will turn over but not crank and seemed as though it wasnt getting any gas. I get out the starting fluid and spray it into the carb and it fires up, only to die again when the fluid runs out. We keep trying for about an hour and the battery eventually died and we put the boat back on the trailer. We took off the fuel line running from the fuel pump to the carb and it had gas in it, but the carb was bone dry. Any ideas? We poured a little gas right into the carb and could get the boat to run but it would quit as soon as the gas that we poured in ran out.

Thanks for your help/suggestions

[Razzman]

Sounds like fuel pump to me. Is it an electrical or mechanical pump? The presence of fuel in the line doesn't mean it's good. If it's a mechanical i'll bet the diaphragm is shot. If electrical i'd check fuses first off and then see if it's pumping.

[JesseC]

Second thing I would do would be to replace your fuel filter. The Ethenol is eating a lot of peoples fuel lines and clogging the filters with small pieces of gummy rubber. Head to the parts store and buy the filter and a fuel pump. If the problem is only with the filter, toss the fuel pump under the helm, you will eventually need it as well!!!

[maxpower220]

You can check the filter, but it is upstream of the carb. You should check the float on the carb. It may be stuck "closed". After sitting for a while, it may not open like it should to allow fuel in. The pump is easy to check: try starting it with the hose disconnected. Mechanical or electrical should push some fuel when the motor is turning over.

[polar21]

I am going to have to look to see where the "float" is in the carb. Not sure what that is but I will look that up. We disconnected the fuel line in between the fuel pump and the carb and turned the motor over, but there was no gas coming out. Should there have been? When we first disconnected it gas came out, but when we tried to start the motor to see if the pump was pumping nothing would happen. I am unsure if I have a mechanical or electrical fuel pump, although there are two wires at the bottom of the pump. The boat/engine is a 1999 Indmar 310hp if that helps.

[zabooda]

You have an electrical fuel pump on the starboard side next to the front stanchion. With the ignition switch on and the engine not running you should hear the pump running. Disconnect the line at the carb, put the line in a gas can and turn on the ignition and gas should be flowing into the can.

[Engine Nut]

You have an electrical fuel pump on the starboard side next to the front stanchion. With the ignition switch on and the engine not running you should hear the pump running. Disconnect the line at the carb, put the line in a gas can and turn on the ignition and gas should be flowing into the can.

The fuel pump on a carb engine does not come on with the ignition. It works only when the engine is either cranking or running. It gets its power during cranking from the starter solenoid and when running from the oil pressure activated fuel pump safety switch that is located next to the distributor. I have attached a diagram. Some of the older switches have three terminals instead of two but they still work in a very similar manner.

[polar21]

Engine Nut,
Do you have any guess as to what my problem might be? My gut tells me fuel pump, but I really do not know.

[zabooda]

Put a power source on the pump and see if it runs. I'll be doing that this weekend when I pump out the old gas.

[fmcmanus3rd]

thanks for the diagram that is the best one I have seen. I just replaced the oil fuel safety switch originally 3 post, new ones only has 2 post and was not sure if i wired correctly. My question now is the fuel pump used to come on momentarily with key turned to the on position now it does not. a real pain if you change fuel filter. Is this the way its supposed to operate?
as to original thread I have had problems with sticking float in the down position and had fuel poring into the carb at an alarming rate. also I think the moombas have had issues with the oil/fuel psi switch mentioned above.
quick way to jump fuel pump to see if working. pull red and purple wires off oil/fuel switch ,turn key on and touch the spade connectors together, or run jumper cables from battery. ground to engine and power to forward electrical connector on fuel pump.you should hear it run..