Carburation/Fuel problems

JGPierce · Post by **JGPierce** » Sun Jul 06, 2008 8:37 am

My '52 M37/42 was sitting since last fall at a repair place waiting for them to fix some cracked transfer case bolts. I picked it up a couple of weeks ago and have been trying to track down a persistent carburation/fuel issue. I'm a bit of a newbie so advice (any) would be helpful.

It starts up right away and idles well. When accelerating from either a stand still or when shifting gears or when the truck is angled (going up or down hills) the engine loses power, sometimes backfires, and sometimes dies. It will start up right away again if this happens. In order to prevent it from dying I have to engage the clutch and tweak the accelerator. Other info: I exchanged the fuel and added a fuel stabilizer.

It sounds to me that the fuel is getting plugged somewhere. I was going to start by cleaning the fuel tank and engine fuel filters, but am reluctant to start until I get some advice. Should I replace the filters or clean them and if clean them then use what solvent? Also, where can I get the correct gaskets as they say to throw them away (part #'s)?

Could this be a fuel sender issue?

Thanks.

MSeriesRebuild · Post by **MSeriesRebuild** » Sun Jul 06, 2008 9:25 am

My first thought with this one is the accelerator pump. I would recommend obtaining a carburetor rebuild kit, disassemble the carb fully, give it a thorough cleaning & a full rebuild. The kit has a new pump plunger & all the necessary gaskets to do the job right.

JGPierce · Post by **JGPierce** » Sun Jul 06, 2008 11:25 am

I've got a carb. rebuild kit and will start on that. Any words of advice? Should I use any sealer on the gaskets? Should I clean it with a particular solvent?

Thanks for the help.

John

Lifer · Post by **Lifer** » Sun Jul 06, 2008 1:29 pm

I agree with Charles about the accelerator pump being the probable cause of your problem. Regarding the fuel filters, however, you should never try to clean them. Just replace them. They aren't that expensive.

MSeriesRebuild · Post by **MSeriesRebuild** » Sun Jul 06, 2008 1:35 pm

JGPierce wrote:I've got a carb. rebuild kit and will start on that. Any words of advice? Should I use any sealer on the gaskets? Should I clean it with a particular solvent?

Thanks for the help.

John

We don't typically use sealer on carb gaskets unless we see a potential trouble spot. You can get carb cleaner at NAPA in a 1 gallon can with a dip basket for small parts, not the good stuff of yesteryear, but does OK if it isn't too bad.

JGPierce · Post by **JGPierce** » Sun Jul 06, 2008 1:45 pm

Great info, guys and thanks. I'll let you know what happens.

JGPierce · Post by **JGPierce** » Tue Jul 08, 2008 6:04 am

I've torn the carb down and soaked everything in cleaner. Lots of shellac and gung is now off and it looks great. Charles, the gallon bucket with the strainer is great to use.
The manual states that the governor should not be taken apart and cleaned in fluid. To be complete I think this part of the carb should be cleaned also and a new gasket placed. Will I run into any problems if I do take it apart?
Secondly, when I replace the gaskets do I put them on dry and bolt everything together?

Lifer · Post by **Lifer** » Tue Jul 08, 2008 9:03 am

I'm thinking that, unless you have lots of experience with governors, you'll run into more problems than you can shake a stick at if you take it apart. There's a reason why the manual says not to do it. If the governor is working, just clean the outside and let it go at that. When it quits working, you can use it as a "learning experience" in governor rebuilding.

JGPierce · Post by **JGPierce** » Tue Jul 08, 2008 11:54 am

Sounds reasonable.

What are people's thoughts on the gaskets elsewhere in the carb (to put on dry)?

TRACTORg25 · Post by **TRACTORg25** » Tue Jul 08, 2008 11:57 am

put together dry. DO not REPEAT DO NOT use any RTV!

Post by **Cal_Gary** » Tue Jul 08, 2008 12:13 pm

Agreed! Also, you might check your fuel cap to see if the vent is open-if it's closed for fording it could be starving your carb of fuel as it creates a vacuum.
Gary

TOM R · Post by **TOM R** » Tue Jul 08, 2008 2:13 pm

our problems were similar even witht he fresh carb, seemed to get better after adding a paper type fuel filter before the fuel pump