Construction and other equipment

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onan generator

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=30499
Printed Date: 02 Aug 2025 at 11:00pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: onan generator

Posted By: fatman
Subject: onan generator
Date Posted: 09 May 2011 at 7:19pm

havent been on here in some time so here goes.

i need help with an old onan gen set i took out of a old motor home. i think it was a 1972. any way its not drawing fuel ffrom my tank to the carb. i cant find anything for the model no. i found, 4.00cklr/9470n serial, 0271286871.

just from a quick eyeballing the pump looks to be about 2 inches around and maybe 4 inche tall. it has one wire or vacuum hose besides the fuel lines going to the pump.

is it electric or gas???? if it is electric i can probably put after market?

let me know what s up or where to look. thanks.

Replies:

Posted By: Tad Wicks
Date Posted: 09 May 2011 at 8:45pm

fatman, whatever your pump is,(it could be an electric pulse pump, some Stewart Warner and Bendix pumps were single wire, but most have two wires, hot and ground) it is probably aftermarket, not Onan. Later Onans and Kohlers both used diaphragm pumps driven by crankcase pulse pressure. Find out if it is indeed electric, when working you can hear and feel them. Good Luck; Tad

Posted By: fatman
Date Posted: 09 May 2011 at 10:25pm

pretty sure the pump is original. it is the funny blue green color still. that is the other problem it dont pump gas. so i cant feel it run. i ll get the covers off and see where the other end of the vac hose or wire goes, then i will determine what type a pump it is?

Posted By: Coke-in-MN
Date Posted: 10 May 2011 at 1:50am

sounds like a bendix pump, some have a removable cover on bottom for fuel filter , new solid state pumps work better than the old ones that were point system pulse pumps.

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Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something.
"Challenges are what make life interesting; overcoming them is what makes life meaningful."

Posted By: dadsdozerhd5b
Date Posted: 10 May 2011 at 7:21pm

sounds like an electric pump, should be controlled from under the shroud by an oil pressure switch if i remember right. you can replace it with a normal electric fuel pump and it is self grounding.

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HD5B, HD5G, (2) FARMALL A's, CUB. DO IT RIGHT THE FIRST TIME, IGNORE THE LAUGHTER. FLANNEL IS ALWAYS IN STYLE.