M Carburetor?

Anonymous-0 · Feb 10, 2011

Having issues getting my M to run correctly.

I have rebuilt the distributor, changed spark plugs, checked timing, ran valves and "rebuilt" carb but my problem persists.

When I start the tractor it runs well but with a little stumble every couple seconds. It sucks in at the exhaust when it stumbles. Once it warms up it gets worse and runs poorly in the mid range and you can hear it stumble at full throttle.

I rebuilt the tractor last year and it ran well all summer. When I first rebuilt it would idle smoothly and only tick the rain cap once in a while but problem got worse and I cant get it right.

Im thinking this is a lean condition in the carb but I cant get it right. Please help.

Charlie M · Feb 10, 2011

I'd try looking for air leaks at the manifold. Make sure it is all tight and no holes have developed on the intack side. Since you had the carb off maybe its leaking there. If using a partial choke fixes the skipping but cause it to smoke its quite likely an air leak.

rustred · Feb 10, 2011

first thing to do is run a compression check on it.

3500sport · Feb 10, 2011

Do you have a good stream of gas coming out at the tank or Carb? Check the petcock at the Carb and if it doesn't fill an 8 oz glass in 30 seconds you have a supply problem move up towards the tank and find your restriction.

(quoted from post at 09:45:55 02/10/11) Having issues getting my M to run correctly.

I have rebuilt the distributor, changed spark plugs, checked timing, ran valves and "rebuilt" carb but my problem persists.

When I start the tractor it runs well but with a little stumble every couple seconds. It sucks in at the exhaust when it stumbles. Once it warms up it gets worse and runs poorly in the mid range and you can hear it stumble at full throttle.

I rebuilt the tractor last year and it ran well all summer. When I first rebuilt it would idle smoothly and only tick the rain cap once in a while but problem got worse and I cant get it right.

Im thinking this is a lean condition in the carb but I cant get it right. Please help.

ChrisMO · Feb 10, 2011

Compression is at 100psi. Gets plenty of gas. Choke doesnt seem to help.

Carb kit did not include main jet, but they look to be clear.

Adjusting idle air screw seems to help. Screw looked a little misshapen, but was not included in carb kit.

rustyfarmall · Feb 10, 2011

(quoted from post at 09:50:09 02/10/11) Compression is at 100psi. Gets plenty of gas. Choke doesnt seem to help.

Carb kit did not include main jet, but they look to be clear.

Adjusting idle air screw seems to help. Screw looked a little misshapen, but was not included in carb kit.

You must have purchased a very basic, gaskets only carb kit.

Anonymous-0 · Feb 10, 2011

This is my reply. Sorry. The computer logged me under a different handle. I guess I need to reserve.

rustred · Feb 10, 2011

did the carb get soaked in carb cleaner? was the valves adjusted hot to .017 in proper sequence as per firing order and rechecked now? you may have a thin margin on a valve and the seat has worn a groove in it and lost your valve clearance.may have a valve leaking. c
ompression @ 100 psi, is that for all 4cyls.? results should be posted for all 4cyls. was the head profesionally rebuilt? guides not worn out? sometimes on paper need a 100 questions answered but when you have visual contact may be a quick diagnosis, as the problem can be spotted with experience and a trained eye.

M Carburetor?

Anonymous-0

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Charlie M

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rustred

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3500sport

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ChrisMO

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rustyfarmall

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Anonymous-0

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rustred

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