General generator system question.....electric fuel pump operation?

[Max Hubrich]

I'm right in the middle of a fuel issue with my Onan Marquis Gold 7000. I've changed out the fuel pump with the exact number called for by Onan.

I found one on Ebay for $40. I had an issue with the "output" end in that the 90 degree fitting was in the incorrect orientation by 90 degrees- It is located in a real tight area under the base plate of the generator. I had to make a new bracket (s) for it to fit into the same space with an additional 45 degree fitting.

It works fine- the prime function is working okay also-- It runs continuously.

But the generator still won't run- I think I have an "Ethanol" issue. I've taken it apart twice now cleaning/blowing it out and re-installing it. It'll start but it won't stay running. A brand new carb is enroute to me now. It only has 162 hours on it. The last time it ran, it was perfect (about 9 months ago). The needle valve and float are fine.

For those interested I'll post a follow up on the new carb installation and if the generator will run properly then.

[pchuckie]

Take the black cover off the altitude adjustment knob on the float bowl of that carb and open the brass screw one or two turns and try it again.

[BFlinn181]

Originally Posted by Max Hubrich

A brand new carb is enroute to me now. It only has 162 hours on it. The last time it ran, it was perfect (about 9 months ago). The needle valve and float are fine.

For those interested I'll post a follow up on the new carb installation and if the generator will run properly then.

Leaving a gas generator sitting 9 months is a sure path to gumming up the carb. It has small passages for varnish to develop. You could run it until the carb is empty, put in Sea Foam, OR, exorcize it each month as the manual recommends.

[ga traveler]

Originally Posted by BFlinn181

Leaving a gas generator sitting 9 months is a sure path to gumming up the carb. It has small passages for varnish to develop. You could run it until the carb is empty, put in Sea Foam, OR, exorcize it each month as the manual recommends.

!00% correct. The new gas is CRAP. The factory does recommend running the generator 30 minutes a month. I asked at the Onan school about running every 3 months for 30 minutes. They said the official rule was once a month. I told them I had done this since 1974 with 3 different motorhomes and no problems. After class both instructors privately said they though 30 minutes every 3 months was enough to keep the gas fresh in the carb. and the wiring dried out. I have had excellent results since 1974 and I make a note in my fuel mileage log every time I run the generator.

[Max Hubrich]

I received the new carburetor today. I installed it right away.

I "primed" the carburetor and hit the start switch- It purred like a kitten. I ran it for about 30 minutes-

Now I have a new pump and a new carburetor.

Then I installed a "on/off" electrical switch on the hour meter bracket. Now I can turn off the electrical fuel pump by flipping the switch and run the carb dry anytime I think I need to get rid of the lousy ethanol fuel.

[pchuckie]

Don't run the carb dry, loosen the drain screw and drain the bowl. When you run it dry it can suck any debris in the bowl into the jet and plug it up.

[ga traveler]

Originally Posted by pchuckie

Don't run the carb dry, loosen the drain screw and drain the bowl. When you run it dry it can suck any debris in the bowl into the jet and plug it up.

There should be no debris in the bowl. The fuel filter should have removed debris from the fuel.

[pchuckie]

We could argue that, but draining the carb bowl accomplishes the same mission as running it dry and precludes any debris getting past the filter.