47 farmall M carb trouble

Mayor · Mar 27, 2009

Here's the rundown guys:
C248 engine, fresh in frame rebuild kit, fresh vavle job, runs great as long as the choke is on.
Tractor had the same problem before I rebuilt the engine but was smoking badly, missing terribly, and no power.....rebuild cured all that but I'm still having too run the tractor with the choke almost all the way on.....gas tank looks new inside, good fuel line, inlet screen is good and clean, the fella I bought the tractor from had installed a new carb kit, I've had it down twice now cleaning and recleaning.....but I'm missing something somewhere.
Adusters arent doing anything and without the choke on....the engine starts hunting and quits regardless of the position of the adjuster screws on the carb.

Any Ideas? Thanks...

ScottyHOMeY · Mar 27, 2009

Larger problems are gonna be either too much air or not enough gas.

On the air side, check for leaks between the carb throat and the manifold, and the manifold and the head. An easy check is to spray a little carb cleaner around those areas with it running poorly and see if it picks up.

It sounds as if you've got her cleaned out okay. Not enough fuel could be a stuck carb float or needle. With the hunting it could also be a poor adjustment of the synch between the governor and the carb.

Those are the first things to come to my feeble mind, and the order in which I'd check 'em out.

glennster · Mar 27, 2009

you dont by chance have an aftermarket in line fuel filter on it?

Mayor · Mar 27, 2009

yes...the tractor has an aftermarket in line fuel filter on it. Someone took the original sediment bowl fuel valve off and put a shutoff valve and fuel filter on it.

I take it this may be a problem?
There seems too be plenty of fuel entering the float bowl....I can remove the brass screw under the float bowl and gas seems too pour steadily.

Also.....something I forgot too mention....today when I put the carb on and turned the fuel on, gas ran out of the bottom of the carb...it done that once before also.....I took a wrench and gently tapped the base of the carb and it quit.

I've also wondered about the float setting in the carb...if its too high or low?

rustyfarmall · Mar 27, 2009

Whoever rebuilt that carb did not do a very thorough job. There is still some gunk way down deep, which is restricting the flow of fuel. Simply soaking the carb in cleaner for awhile is not sufficient.

glennster · Mar 27, 2009

pick up a sediment bowl and remove the inline filter. most in lines are designed for a pressurized fuel system and wont flow enough fuel for a gravity flow system. if you cant get a sediment bowl quick, go to napa and get either a 3031 or 3032 inline filter. it is a good size metal cannister filter that is a full flow and will work reasonably well on a gravity system.

old · Mar 27, 2009

I agree with Glen, in line filters are a big problem. When ever I go fix a tractor for some one with the problem you have I throw the filter in the back of my truck and charge them a case of beer for my trouble. I'm past 20 case now over the last 4 or 5 years LOL. Install a new sediment bowl, $20 or so new and be done with it, and yes you probably will have to play with the carb also but I would start with the sediment bowl and maybe you will get lucky that, that will fix your problem
Hobby farm

Anonymous-0 · Mar 27, 2009

Plugged intake / restricted, or vacume leak as said before. I can't think of anyone goofing up on a carb twice.

47 farmall M carb trouble

Mayor

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ScottyHOMeY

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glennster

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Mayor

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rustyfarmall

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glennster

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old

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Anonymous-0

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