losing my hair

barefoot

New User
I don't have enough to be giving up any more. I have a new to me 1948 8n front mount distributor. It sputters and dies above 2/3 to 3/4 throttle. I put a new water pump on it. It came with a new carb and distributor installed. I did a tune-up (new points, condenser, plugs, wires, not coil). Also rebuilt the carb with an ultrasonic bath. Check the fuel flow and fuel filters. It runs if I pull the main needle out or choke the engine. The tractor had set for at least 5 years before I got it. The plugs were sooty black when I pulled them. I'm running out of ideas. I figure that it is in the fuel system.

Thanks, Bill
 
"It came with a new carb" That could be your problem. Ditch that new carb, buy an original MS carb on ebay, rebuild it and install it. Lots
of posts in the archives that chronicle the unreliability of new carbs. If you lived near me I would loan you one of my back up carbs to test
it.
 
(quoted from post at 16:16:44 05/01/18)
I figure that it is in the fuel system.

have u checked your fuel flow? with the valve at the sediment bowl open, and the plug removed from the bottom of the carb, the flow should fill a pint jar in 2 minutes or less.

by any chance, is it low on gas? if so, try pouring in a couple more gallons. the reserve pickup on these sediment bowl assemblies is notorious for plugging. adding a couple of gallons gets u back up to the regular pickup.
 
Either your float is set
too lean or you still
have a little crud in
csught in the carburetor.
Try a can of seafoam in
the gas tank. Run the
enginelong enough to
where you know the
carburetor is full of the
mix. Then let it sit over
night. That may loosen up
the crud, but won't help
with the float setting.
You'll have to look at
that if the seafoam
dosn't work.
 
Similar problem on a Rochester B on my 52 Chevy
PU, would not run unless it was almost fully
choked. Found the gasket between throttle body and
float bowl was bad and sucking air, thusly with
choke reducing air flow it would run. Sooty
interior of carb and exhaust. Rebuilt carb and
runs smooth.
 
I set the float with a 1/4" drill bit as a feeler gauge. I don't think it is electrical because it runs fine with out the main needle installed in the carb.
Guess I'll have to find some Seafoam. It has good spark on #1 cylinder, the only one I checked.
 
(quoted from post at 01:37:07 05/02/18) I set the float with a 1/4" drill bit as a feeler gauge. I don't think it is electrical because it runs fine with out the main needle installed in the carb.
Guess I'll have to find some Seafoam. It has good spark on #1 cylinder, the only one I checked.

Lucas makes a good fuel system additive too if you can't find any sea foam.
 
I don't think it is electrical because it runs fine with out the main needle installed in the carb.

As already mentioned, it's running lean.

A vacuum leak at the carb body parting line, carb to manifold junction or manifold to block would also induce a lean air/fuel mixture. Put the main needle back in and spray those areas with starting fluid while tractor is running. If it smooths out, you've found the leak.
 
(quoted from post at 01:37:07 05/02/18) I set the float with a 1/4" drill bit as a feeler gauge. I don't think it is electrical because it runs fine with out the main needle installed in the carb.
Guess I'll have to find some Seafoam. It has good spark on #1 cylinder, the only one I checked.

One thing I forgot to mention. For a situation like you're experiencing you need to use more sea foam than the directions on the can prescribes. Put one can of sea foam in about five gallons of gas, two cans in ten gallon, and so forth. I had an International 340 that was acting like your tractor is. I had to pull the choke all the way out just to make it run. I figured it had about ten gallons of gas in the tank, so I dumped two cans of sea foam in with the gas. I then drove the tractor around a little to help mix the contents of the gas tank, and making sure the carburetor bowl would be full of the mix be fore shutting off the engine. The next day I started the tractor with the choke pulled all the way out. When the engine started it I had to push the choke back in before it flooded the engine with gas. The engine ran like it was supposed to after that.
 
I had the same problem after installing a new carb, finally removed it, and installed the old carb, took it apart and cleaned it before I installed it , but it runs like a champ now. I have no idea why the new carb does not work right, but I am sticking with the Original carb.
 
Lots of problems with aftermarket carbs, starters, governors, etc. Not too difficult to find OEM parts that are repairable.
 
update

Seafoam didn't solve the issue. Spraying starting fluid on the seams didn't solve it. Thinking about what I have done to the tractor I remembered that the sediment bulb had some thing that looked like baking soda in it. So back to the ultrasonic cleaner went the carb. After several rounds laying in different positions, reassembled, and installed. I think the issue is resolved.
 
(quoted from post at 02:14:54 05/05/18) update

Seafoam didn't solve the issue. Spraying starting fluid on the seams didn't solve it. Thinking about what I have done to the tractor I remembered that the sediment bulb had some thing that looked like baking soda in it. So back to the ultrasonic cleaner went the carb. After several rounds laying in different positions, reassembled, and installed. I think the issue is resolved.

Sometimes it takes a little more effort to get the small passages in a carburetor cleaned out. What were you using in the ultrasonic cleaner as a cleaning agent? Sometimes just soap and water will do the job. I found that paint thinner and naphtha works pretty good. I mix it 75% paint thinner and 25% naphtha.
 
I usually use hot water, simple green and a teaspoon of "lemishine" (dishwasher additive to help keep the grime from settling back on the parts). This works well for my motorcycle carbs too. I think they soda blasted the tractor and some got into the carb.
 
(quoted from post at 02:12:58 05/06/18) I usually use hot water, simple green and a teaspoon of "lemishine" (dishwasher additive to help keep the grime from settling back on the parts). This works well for my motorcycle carbs too. I think they soda blasted the tractor and some got into the carb.

Maybe some thought it was a good idea to clean the inside of the tank with the soda blaster? Could be more of the stuff in there waiting to plug up the carburetor again.
 

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