Ford 841 Carburator Problem!!!

[strum456]

I have been fighting with this for longer than I'd like to admit. I have a nice 841 with PS and a Sherman over/under. BUT, the tractor is almost unusable because you never know when the carburetor is going to start acting up.

For example, tonight we ran the mower conditioner for an hour and a half with no problems. With only a few rounds left, it shut off. It started right back up, mowed for a minute and then shut off. We repeated this process about 10 times before getting another tractor.

What has been done so far:

1. Checked fuel cap - not an issue. Problem occurs with no cap
2. Checked fuel flow to the carburetor - there is plenty.
3. Vapor locking - I re-routed the fuel line towards the front of the engine and down to the carb. to keep it away from the manifold heat.
4. Checked float height and verified no contact with float bowl. I wiped grease on the inside of the bowl and rattled the float around to see if any grease rubbed off.
5. Replaced float valve needle and seat.

The only thing I can think of is the float is hanging up, but I have checked everything many, many times. I cannot find any reason why the float would be sticking. I have noticed that the more gas you have in the tank, the less of a problem this is. I had a 1/2 tank when it started shutting off tonight.

 

[RickB]

When it quits, immediately remove the drain plug from the carb bowl. If it has fuel, you don't have a carb problem. I suspect an ignition circuit problem, possible a faulty key switch or bad connection in that circuit. A faulty ignition coil or condenser would take more time to cool and go back to working. It isn't likely that the needle valve will stick closed on a running tractor. The valve will be in a partially open state.

 

[strum456]

Thanks Rick. It usually starts right back up. I really think it is a fuel problem. I have double checked the wiring. It is all new, as are the points, condenser and key switch. The tractor was already 12v when I restored it, so I didn't replace the coil.

I think it is a fuel problem. The problem is worse when operating under a heavy load (like discing in a higher gear). The problem rarely happens with a full tank. When it shuts off, it doesn't seem like the float is completely stuck shut, but more like it just isn't getting enough gas. If I hear the engine missing, I can sometimes push in the clutch and let it idle for a while and go back to work.

 

[Soundguy]

does it only do it when 'hot' or running after X minutes


do the fuel check at the bottom of the carb like rick says.

if it's not fuel.. hotwire the coil and run it a bit like that. ( bypass key switch and any other connections that may be bad..e tc. )

also check for fuel tank vacume..

 

[RickB]

A new key switch doesn't mean much. Seen several that were junk out of the package and the expected life of them is not the greatest, especially if the wiring has been altered & the light load runs through the key switch along with the ignition circuit.
Immediate restart doesn't sound like fuel to me, but I can't see it very well from here.

 

[strum456]

I'll hot wire the coil and try raking with it tomorrow. I have already pulled the float bowl drain right after it quit and little or no fuel came out. But, it has been a while since I've tried that, and I've messed with the carb. since then. Now that I have two of you telling me to check the electrical system, I'll try it just in case. .

 

[Soundguy]

pulling the drain and nada coming out is not a good sign mind you....

 

[RickB]

I have already pulled the float bowl drain right after it quit and little or no fuel came out.

I must have missed that the first time you told us.

 

[Soundguy]

I must have missed that the first time you told us.

i don't see it in the posts anywhere. just post 1 saying carb was getting plenty of fuel.. etc.

 

[strum456]

Ok guys, here's the dilemma:

I took the tractor out to rake. After 10-15 minutes, it started acting up. Just like it was running out of gas. During this time, the coil was "hot wired", just in case. When the tractor shut off, I pulled the drain on the carb as fast as I could and fuel came out. I limped the tractor back to the garage and pulled the carb. (there was plenty of fuel in it). I cleaned all the jets, holes, etc with carb cleaner and compressed air. After reassembly, the tractor would not start. A sputter now and then was all it would do. I checked the spark, it was strong and blue. I cranked the main jet all the way out, all I would get is a sputter. I tried starting fluid, then the tractor started right up but then shut off as soon as the starting fluid was gone. So, I pulled the carb back off (which was full of gas). I cleaned everything AGAIN. Put it back on, and still nothing more than an occasional sputter.

So, it runs on starting fluid. The float bowl is full. I have tried the main jet in various positions and I've taken a lot of care in cleaning all parts of it. WHAT THE HECK???:confused2:

I have to go bale now. Hopefully you guys can give me something to try on this tractor when I'm done.