Onan B48m carburetor pump issue

612 Views 16 Replies 6 Participants Last post by Harry, 20 d ago

Hu Go

Discussion Starter · 27 d ago

Hi all, I’ve about exhausted all ideas to get my pump to work. Any recommendations on a pump I should purchase. Or any ideas on how to get it working?

1 - 17 of 17 Posts

Lionel

· #2 · 27 d ago

So, firstly,
Have you tried direct feeding the carb? Does it run?
Replacement pumps aren't that much, some like the mechanical ones, but my preference is an electric fuel pump.
Facet Posi-Flo Fuel Pump

www.aircraftspruce.ca

Facet Posi-Flo Solid State Fuel Pumps | Aircraft Spruce Canada

Facet Posi-Flo Solid State Fuel Pumps All models of the Facet Posi-Flo Pumps are compatible with gasoline, diesel, biodiesel, blended alcohol fuels and fuel additives.

www.aircraftspruce.ca

#60304

Reactions: 1

Hu Go

Discussion Starter · #3 · 27 d ago

I’m very sold on the electric pump. Can you send a photo of how your rigged it? Did you leave the old pump in place? If so did tinker with it to allow the fuel to flow through?

mendonsy

· #4 · 26 d ago

I don't have any photo of my installation, but I installed one under the frame of my 446 just ahead of the fuel tank. It has been working fine for about 10 years now. If you get the low pressure version (1.5-4 psi) you won't have to do anything to the existing pump. The electric pump just needs to provide enough pressure to lift the fuel from the tank up to the existing pump.

Reactions: 3

Lionel

· #5 · 26 d ago

Here's some lite reading that I'd posted, and others have as well.

www.casecoltingersoll.com

12 volt fuel pumps

I quite like the 12 volt fuel pumps, doesn't matter how long the motor has sat, It'll start in 1 or 2 turns of the motor. Now, I've been buying my 12 volts from David kirk and his certainly works nice. I was hanging out on aircraft spruce,, and came across this little pump. Anyone try this...

www.casecoltingersoll.com

www.casecoltingersoll.com

I don't think I ever took decent pictures of locations to mount these. The last one I did, about 3 years ago,
All I did was cut the inline fuel hose coming from the tank, to the filter. I zip tied the thing to a convenient spot under the frame, wired it up, (Needs a good ground, so I went from batt ground to the unit) the positive, I just used the same wire from ignition switch that goes to the coil,, (That wire, is positive with key on) and the wiring was done.

On the old pulse pump, I just disconnected the pulse line, plugged it up, with a bolt and a clamp and called it a done. (Likely took about 30-40 minutes all told.

The benefit of the electric pump is, no matter how long the motor sits, turn key on, wait for a couple of seconds, and fire it up in a couple of cranks.

See less See more

Reactions: 1

Hu Go

Discussion Starter · #6 · 26 d ago

Thank you both! This is extremely helpful. I ordered the pump and will let you know how it works.

Reactions: 1

Hu Go

Discussion Starter · #7 · 25 d ago

Hi, one more question. Did you by chance use a pressure regulator when mounting the electric fuel pump?

mendonsy

· #8 · 25 d ago

Hu Go said:
Hi, one more question. Did you by chance use a pressure regulator when mounting the electric fuel pump?

I did not. Mine is a 1.5-4 psi Facet pump which did not need one.

Hu Go

Discussion Starter · #9 · 21 d ago

Hello, so i attached the pump changed the lines and the fuel gets to the he carb but isn’t making it’s way to the cylinders. I i have taken this carb apart and at this point i’m ready to buy a new one. Any recommendations on what to do or what carb to buy?

Lionel

· #10 · 21 d ago

A good cleaning?

Reactions: 2

bhildret

· #11 · 21 d ago

Which carb do you have? M/S DD13 or Nikki?

Or what's the PIN/Serial number on the tractor chassis?

Bri

Hu Go

Discussion Starter · #12 · 21 d ago (Edited)

i have the DD 13. I tried bypassing the pump and everything. Just rather get a new Carb. Trying to get an idea what is the best replacement that wont cost an arm.

bhildret

· #13 · 21 d ago

What's the PIN/Serial number on the TRACTOR chassis?

Or post a photo of the carb.

Brian

ras101

· #14 · 21 d ago

Hu Go said:
I’m very sold on the electric pump. Can you send a photo of how your rigged it? Did you leave the old pump in place? If so did tinker with it to allow the fuel to flow through?

Hu Go. I spent months following advice here about manual/electric pump options for my 1977 BF engine. You know what? I just found and went with an electic low volume pump and never, ever, regretted my options. Just go for it!!!

Reactions: 2

Lionel

· #15 · 20 d ago

Hu Go said:
Hello, so i attached the pump changed the lines and the fuel gets to the he carb but isn’t making it’s way to the cylinders. I i have taken this carb apart and at this point i’m ready to buy a new one. Any recommendations on what to do or what carb to buy?

I don't know why your carb wouldn't be working, Does the carb fill up with fuel? You can tell by just pulling the carb top off.

After that, the only problem would be a problem with the tiny little orifices that feed the intake,, Did you run cleaning tips through the little orifices?

As well, can you post a couple of pics of your setup?

Reactions: 1

Hu Go

Discussion Starter · #16 · 20 d ago

You nailed it. One of the little orifices is clogged and i cant get anything through it. I have a feeling the prior owner was cleaning it and got something wedged in there. Tried tiny wires, air pressure, and carb cleaner but it just kept shooting back out the way it was coming in.

Harry

· #17 · 20 d ago

You might try cutting torch cleaning wires. They are stiff cleaning files for torch tips. Not very expensive and work great IMO. ✌Harry

Reactions: 4

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