Green Tractor Talk banner
1 - 10 of 10 Posts

·
Registered
Joined
·
165 Posts
Discussion Starter · #1 ·
P218G Onan
Carb has been rebuilt, intake has been sealed, intake gaskets replaced with OEM, Electric fuel pump.
There is fuel in bottom of inline filter.

What can I say? This thing is just simply cold blooded. If it sits for a long time........... weeks or longer, I have to remove everything from top of carb and drop a little gas down its throat before it will fire.

Is there such as an inline primer bulb for the fuel line?

Suggestions?
 

·
Registered
Joined
·
15 Posts
They do make some inline primer bulbs and I picked up a few on Amazon last year but I never did try them out as I found another problem before they arrived. You could also pick up a small inline check valve to keep the fuel from draining back. I do use these because my 316 is hard to start after a week or two as well and this has helped.

1/4" check valve at US Plastics
 

·
Registered
Joined
·
1,829 Posts
Edited: I see you have an electric fuel pump, so ignore my earlier text below... The electric pump should prime everything if it is working correctly. Is the choke plate working correctly?

Sounds like your fuel is running back into the tank while setting, making starting require a lot of cranking. Try turning the fuel selector valve to the middle (OFF) position when shutting down to see if less cranking time is needed when yo open it back up for the next start.

You may also have a failing fuel pump, or some air leaks in the hose from the crankcase to the pump that powers it all...


Chuck
 

·
Registered
Joined
·
165 Posts
Discussion Starter · #4 ·
Edited: I see you have an electric fuel pump, so ignore my earlier text below... The electric pump should prime everything if it is working correctly. Is the choke plate working correctly?

Sounds like your fuel is running back into the tank while setting, making starting require a lot of cranking. Try turning the fuel selector valve to the middle (OFF) position when shutting down to see if less cranking time is needed when yo open it back up for the next start.

You may also have a failing fuel pump, or some air leaks in the hose from the crankcase to the pump that powers it all...


Chuck
There is fuel in the inline filter when pump kicks on.
Choke plate is working correctly.

BTW: the electric puel pump is a low pressure pump, is that the correct pump to use?
 

·
Registered
Joined
·
2,356 Posts
A low pressure filter is the correct pump, around 2-4psi. If you install something around 8+psi, it will over-ride the needle & float and you'll have gas all over everything!

Some fella' use a prime bulb to get fuel back into the carb after sitting for a while. Bob
Like this:
Violet Cylinder Auto part Magenta Audio equipment
 

·
Registered
Joined
·
1,829 Posts
Sounds like your fuel delivery is working as it should. Have you tested the compression of this engine? It could be at or below the minimum when cold and that would make it harder to start...

Once started, does it run correctly when warmed up? Does it have decent power? Onans have been known to "run" on one cylinder but have hard starting and low power issues, of course.

Chuck
 

·
Registered
Joined
·
165 Posts
Discussion Starter · #7 ·
It seems to run right "after I get it started".
Seems to have good power as well.

I'm pretty sure it's running on both cylinders, I would be sure to know that if it wasn't.

BNTW: I have seen this motor run backward a long time ago, believe it or not.
 

·
Registered
Joined
·
1,829 Posts
Please video that!! Can't conceive of any four-stroke engine running backwards due to the sequence of valve openings, etc... Maybe if the engine were a diesel it could briefly do that. Anyone know for sure?

Chuck
 

·
Registered
Joined
·
165 Posts
Discussion Starter · #9 ·
I know for sure. It happened several times years ago.
I was laying underneath the tractor with belly screen off trying to grease the driveshaft universal joint. Reaching up around and trying to blip the key to get the grease fitting pointed in the right direction. blip blip blip several times. A couple times when the motor stopped on a compression stroke and rotated backward, I blipped the key again and it ran backward. I could see the driveshaft turning the wrone way/ I.m telling ya.
 

·
Registered
Joined
·
1,829 Posts
OK, easy to see where it could fire well before TDC (turning on/off the key with your 'blip' is the same as the points opening to make the field collapse in the ignition coil and fire the plug) and that would propel it in the backward rotation position. The moment the key is turned off is also how you might get a 'backfire' on an engine that otherwise does not have a functioning set of points, etc.

I can't imagine the engine continuing to run in reverse if you had left the key in the ON position in the situation you describe above... Thanks for describing your experience. (y)

Chuck
 
1 - 10 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top