Problems with 2072

[drcjv]

Ok still not solved I have replaced the gas tank,carb and air cleaner from another working 2072. The engine would not turn over as the cylinders filled with gas from a bad fuel pump. The oil was full of gas also. I blew out the cylinders, changed oil and filter and put on a new fuel pump. After all that I still have problem. The tractor starts and runs for about 20-30 seconds then dyes. I can bottle feed through the carb and keep it running. Also I took the line off the carb when cranking the gas flows out the end but is not blowing out only maybe a 1/2 inch from end not sure if it should be more. At this point I'm not sure where to go next. Is the new pump bad? Should it have more pressure? It starts and runs just won't keep running.

[sorner]

Originally Posted by drcjv

Ok still not solved I have replaced the gas tank,carb and air cleaner from another working 2072. The engine would not turn over as the cylinders filled with gas from a bad fuel pump. The oil was full of gas also. I blew out the cylinders, changed oil and filter and put on a new fuel pump. After all that I still have problem. The tractor starts and runs for about 20-30 seconds then dyes. I can bottle feed through the carb and keep it running. Also I took the line off the carb when cranking the gas flows out the end but is not blowing out only maybe a 1/2 inch from end not sure if it should be more. At this point I'm not sure where to go next. Is the new pump bad? Should it have more pressure? It starts and runs just won't keep running.

I don't think a bad fuel pump would fill the cylinders, would it? That sounds more like a stuck float needle valve to me.

[drcjv]

Originally Posted by sorner

I don't think a bad fuel pump would fill the cylinders, would it? That sounds more like a stuck float needle valve to me.

I don't know either but I changed the carb already.

[Oak]

Charles, I'm thinking you have another carb issue if you can bottle feed it to keep it running. On my 1811, I bypassed the failed pump for 2 years and it ran normal with gravity flow from the tank as long as I kept it above the level of the carb. I think you already did this but if your sure the tank, fuel cock and lines are good then it's gotta be the carb. Did you replace the line from the pump to the carb?

[drcjv]

Originally Posted by Oak

Charles, I'm thinking you have another carb issue if you can bottle feed it to keep it running. On my 1811, I bypassed the failed pump for 2 years and it ran normal with gravity flow from the tank as long as I kept it above the level of the carb. I think you already did this but if your sure the tank, fuel cock and lines are good then it's gotta be the carb. Did you replace the line from the pump to the carb?

Oak the carb was taken off my other 2072 that has been running fine for years.
I was told by an old cub guy that if the cylinders were full and the oil was full of gas the fuel pump was bad. I pulled the line off my 1872 to see how much pressure the pump had and it was more than the 2072. It will run for about 15 20 second before it wants to dye. I can only think that I got a bad pump. Not really sure what to do now.

[sorner]

You know, a bad fuel pump can cause that. I wasn't thinking straight earlier. If the diaphragm in the pump fails it can suck gas through it into the crank case through the vacuum tube.

[flatpickerray]

FWIW this happened to my 782 a couple years ago. The cylinders filled up with gas and the engine wouldn't turn. I thought I thru a rod or something. I had rebuilt the carb. but failed to notice the float had a very small hole in it. So that's one more thing to check if you haven't already. Ray

[Oak]

The only way the cylinders can fill with gas is if the float doesn't shut the fuel off. The sump can fill if the pump fails and gas is sucked in to it.

The pump is not needed. Fill the tank 1/2 full and your carb will be below the fuel level and work normal.

I'm thinking your pump failed and you have trash in the line from the pump to the carb and it is clogging the carbs up.

I would pull the carb and give it a good cleaning, replace the line from the pump to the carb and install a good metal type fuel filter between them.

Lets us know how it goes Charles. Good luck.

[drcjv]

Originally Posted by Oak

The only way the cylinders can fill with gas is if the float doesn't shut the fuel off. The sump can fill if the pump fails and gas is sucked in to it.

The pump is not needed. Fill the tank 1/2 full and your carb will be below the fuel level and work normal.

I'm thinking your pump failed and you have trash in the line from the pump to the carb and it is clogging the carbs up.

I would pull the carb and give it a good cleaning, replace the line from the pump to the carb and install a good metal type fuel filter between them.

Lets us know how it goes Charles. Good luck.

I filled the tank and still have the same problem.

[Shrewcub]

Take the carb off and clean it. Make sure the float floats and check the needle and seat.