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Tgalo

Hard starting after sitting Onan

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Tgalo

One more question, my 520 takes many cranks to start after it sits for a day or two. I found a loose plug on the carb that I thought was draining the gas when it sat. Tighten that plug didn't help. Do I need a check valve in the fuel line? It runs strong after it starts. My 418 with a Kohler fires right up after weeks of sitting. Thanks, T

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Ed Kennell

Sounds like the classic under the seat tank problem.  The fuel drains back to the tank with time and the fuel pump loses it's prime.

 

several solutions are 

1. add a shut off and remember to close it

2. add an electric fuel pump

3. add a marine primer squeeze bulb

4. fill the fuel tank when parking for a long time

 

I have added the primer bulb to all my tractors and now they all start instantly

 

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lynnmor

Some claim that a check valve improves the starting, but my thought is #2 or #3 in Ed's post are the complete fix.

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Ed Kennell
7 minutes ago, lynnmor said:

#2 or #3 in Ed's post are the complete fix.

If the fuel pump is working OK after start up, #3 the primer bulb is my recommended fix.   inexpensive, easy to install,  always works.

If the pump is failing, go to #2, the electric pump.

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clueless

I've got the marine primer bulb on all three of my under the seat gas tank WH's, best $10.00 thing I every did for them. I have them connected to the fuel line under seat and zip tied. Lift the seat about 4 or 5 good squeezes and they fire right up even the 312. On the one I plan on using every week or two about 1 o 2 squeezes, on the ones I don't plan on using for a long period of time I turn of the fuel at the tank and run it till it stops, don't forget to turn your key off after it stops are when you go to start it again you will have a dead battery and at least 150 hr or more added to your hour meter trust me :rolleyes:. When I go to use it again open up the fuel line about 8 good squeezes and she fires right up :handgestures-thumbupright:

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Ed Kennell
18 minutes ago, clueless said:

best $10.00 thing I every did for them

 

Your batteries and starters will luv you and last forever.

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pacer

In case you go choose the electric pump route, be sure and get one that is LOW pressure -----

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clueless
16 minutes ago, Ed Kennell said:

 

Your batteries and starters will luv you and last forever.

:handgestures-thumbupright::handgestures-thumbupright:

Edited by clueless

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Tgalo
3 hours ago, Ed Kennell said:

I have added the primer bulb to all my tractors and now they all start instantly

 

Where do you put it that its not noticeable? 

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tom2p

knock on wood - no fuel pump problems - although will need to crank for a bit in cold weather when a tractor sits for weeks 
 

I will often add a small amount of Sta-bil ... MMO ... 2-stroke mix ... motor oil ... whatever ... to the gas I use in small engines including the Wheel Horse tractors 

 

I wonder if this will help to keep the fuel pump parts (including diaphragm ?) more pliable / better shape ?

Edited by tom2p

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tom2p
12 minutes ago, Tgalo said:

 

Where do you put it that its not noticeable? 


not noticeable might then equal not easy to reach  (?)

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lynnmor
2 hours ago, clueless said:

On the one I plan on using every week or two about 1 o 2 squeezes, on the ones I don't plan on using for a long period of time I turn of the fuel at the tank and run it till it stops, don't forget to turn your key off after it stops are when you go to start it again you will have a dead battery and at least 150 hr or more added to your hour meter trust me :rolleyes:

The Onan’s have an oil pressure switch that prevents the hour meter from running when the engine is not running.

 

I wonder if the $10 squeeze bulbs are good, there are many out there with bad reviews.

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Ed Kennell
53 minutes ago, Tgalo said:

 

Where do you put it that its not noticeable? 

I do not attempt to hide mine.    I put them between the steering column and the engine where I can reach thwm from the seat.

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clueless
2 hours ago, lynnmor said:

The Onan’s have an oil pressure switch that prevents the hour meter from running when the engine is not running.

 

I wonder if the $10 squeeze bulbs are good, there are many out there with bad reviews.

A lot of electric fuel pumps out there with not so great reviews either, I guess it's all a crap shoot.

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