Problems after carburetor rebuild

[ridgeandvalley]

Hoping some of you can give me some good advice and save me some time figuring out where to start looking to solve a carb problem. I had a problem last fall with my Ford 960 w/ Marvel Schebler carb. Turns out the screws holding the throttle butterfly had come loose (disappeared) and the tractor roared full throttle when I started it. So, this spring I got a basic rebuild kit and replaced those screws on the throttle butterfly in the carb. Decided to do a thorough cleaning as well while I had it off. Didn't really replace anything else except gaskets. When I put it back on the tractor, it started back up easily enough considering it had sat all winter long without running. After a few minutes, just about when I thought it was warmed up enough to take for a little test run, it started to sputter and died. I didn't have time right then to dig into it, but when I went back a couple of days later, it would not start. Turns over, but not catching. Obviously, spark and fuel are the first places to check, but the fact that it was running and then suddenly wasn't makes me wonder. I'm really slammed with work right now, and it seems every weekend there's been something else that needs to get done, or someplace to go, and I'm getting a little nervous, as I am probably 2 - 3 weeks away from doing my first hay cutting, and I don't really have a backup tractor. I'm hoping that somebody can save me some wasted time and wrong turns in getting this tractor running again. Thanks.

 

[pomester]

If it "sputtered" before it stopped it likely ran out of fuel. Remove the small plug on the bottom of the carburetor and see if there is a good continuing flow of gasoline.

If there is, check easy electrical. See that there is power to the coil when the key is turned on. If so, pull the coil wire and see if there's a good blue spark when you crank the engine.

It's got to be one or the other.

Easy, quick test - a shot of ether. if it fires, it's a fuel problem, if it doesn't it's electrical.

 

[Eman85]

I always like to look at the spark plug and see if it's wet from gas or dry. Of course this is best done when you first have the problem. It does sound like it ran out of fuel so pulling the drain on the carb and see if you have good flow out of it with the fuel on is a good place to start.

 

[jimtrs]

(quoted from post at 15:20:42 05/14/21) .... When I put it back on the tractor, it started back up easily enough considering it had sat all winter long without running. After a few minutes, just about when I thought it was warmed up enough to take for a little test run, it started to sputter and died.

Possible your carburetor bowl filled up with fuel the first time (when float and needle were down), then when the float raised and the needle valve closed, it did not open back up to allow more fuel to the bowl. Hence, run out of fuel after one bowl full.

This can happen a couple different ways. One way is the needle gets stuck in the seat. Happens sometimes with the rubber Viton tip needles. If that is happening try taking a fat toothpick and burnish the seat. If your carb has the little clip between the needle and float, make sure that is hooked up correctly and as the float drops, it pulls the needle down with it.

Another way to they stick closed is the float itself hangs up on the sides of the bowl. Happens. Particularily after having the carb open. Make sure the float didn't get bent or cocked, and is operating throughout its range freely.

 

[showcrop]

As eman said take a spark plug reading. This will tell you quickly and easily if it is getting gas into the cylinders. When a gas engine is cold it needs a rich gas mixture in order to fire. An adequately rich mixture will make the plugs wet. If they are dry pursue the procedure as jimtrs described.