1953 40U

[JRN Sr]

With an updraft carburetor how did I get gas in the oil?

 

[beenthere]

Welcome to TBN
What has led up to this happening? Must be some history behind the problem. Bring us up to date a bit.

 

[JRN Sr]

Just bought the tractor and it is puking oil, waiting on compression test that will be here Wednesday to check compression. I understand when the needle in a carb sticks and floods gas but not on an updraft carb. Just curious if anyone else has run in to this issue?

 

[beenthere]

But starts and runs okay? or runs but not good? what do you observe?

 

[DJ54]

Just bought the tractor and it is puking oil, waiting on compression test that will be here Wednesday to check compression. I understand when the needle in a carb sticks and floods gas but not on an updraft carb. Just curious if anyone else has run in to this issue?

If the fuel level in the tank is/was higher than the manifold intake ports in the head, and air cleaner hose connections were good & tight, like any other liquid it will seek its own level. That also means the air cleaner is also full of gas up to the level of the intake ports where the manifold attaches to the head.

 

[rScotty]

If the fuel level in the tank is/was higher than the manifold intake ports in the head, and air cleaner hose connections were good & tight, like any other liquid it will seek its own level. That also means the air cleaner is also full of gas up to the level of the intake ports where the manifold attaches to the head.

Yep. DJ has it. The updraft carb can be lower than the engine, but if the fuel tank is above the engine, then that's how the fuel gets up into the intake manifold. It's not where the updraft carb is, it's where the fuel tank is. All it takes for that to happen is a stuck float bowl needle and a plugged carb vent....both very common problems.
Kit the carb. change oil, dry out the system.

 

[JRN Sr]

Yep. DJ has it. The updraft carb can be lower than the engine, but if the fuel tank is above the engine, then that's how the fuel gets up into the intake manifold. It's not where the updraft carb is, it's where the fuel tank is. All it takes for that to happen is a stuck float bowl needle and a plugged carb vent....both very common problems.
Kit the carb. change oil, dry out the system.

 

[JRN Sr]

No gas in the oil bath. I ordered a pan gasket, so I plan on draining the oil drop the pan and see how clean it is, look at the oil pump screen. Change the filter fill it up and go from there.

 

[rScotty]

On our gasser - a JD 2 cylinder - there is no way for gasoline to get into the oil bath air filter since it is above the carb and the intake manifold. But it could sure get into the engine oil.

At the very least, put a new float needle in the carb or clean the old one. Also check that the float still floats, and make sure the float bowl vent is clear. With the new gasolines I often have to do those things if I let the old gas tractor sit for a winter without being started and worked.

If the carb float bowl vent is open (wasps will plug them with mud) then sometimes you can cheat and get a stuck float needle unstuck by just opening the fuel petcock enough to fill the carb float bowl - about 10/15 seconds. They turn off the petcock, start it and let it run until just before it starts to stagger, then open up the petcock again to fill the bowl again. Tap on the carb and repeat that sequence for a few times. If the problem is just a stuck float needle that will clean it up just often enough to be worth trying.

rScotty

 

[DJ54]

Looking at a picture of the 40U, it looked like the top of the air cleaner connection is lower than the manifold ports and why I thought it may have gas in it too. I had an MT years ago but sold it. Nice tractors.