International U-6 Power Unit Carburetor problem

Anonymous-0 · May 18, 2012

I have an International U-6 Power Unit operating a sawmill. I understand that this engine is the same as the Farmall Super M with possibly minor differences. I bought this mill with the U-6 about three years ago and have reconstructed the mill on my property. The motor runs great up to and at the 1450 rpm's that is required to operate the saw but falters when the saw engages a log and the governor attempts to compensate for the loss of rpm"s. I have rebuilt the fuel pump and carburetor (E12 updraft), converted the magneto (H4) to a distributor, replaced the governor spring. I went through the timing numerous times, cleaned and re-calibrated the carburetor numerous times. The compression is about 105 psi on each of the cylinders. I do not believe it is a valve problem. The engine was originally designed to use kerosene or distillate gasoline but I understand it will burn modern gasoline with out there being a “fuel type” issue. I have been working on this problem for many month with minimal improvement. Anyone have any suggestions?

teddy52food · May 18, 2012

If there is a main jet adjustment, can you open it up so the exaust smokes black? If not there is crud in the main jet circuit. Or try setting the float a little higher.

Haas · May 19, 2012

Sounds like you have a fuel issue; not getting enough. Maybe the carb float is set too low or more likely, you have some crud in the fuel tank and it is causing restriction of fuel flow. You may think you have everything clean, but it does not take much to cause problems. I could not get my U-2 power unit to start easy and run well until I put a fuel filter in the line. The fine crud was getting though the screen in the sediment bowl and causing carb problems. Since I put the fuel filter in the line, it starts when cold with no more than two or three pulls of the crank (it has a magneto and no electric starter) and after it's warm usually only one pull. I use NAPA 3032 fuel filter which has a metal case and is designed for gravity flow. The 3032 is for 5/16 fuel line. They also have the same filter for 1/4 and 3/8 fuel lines (different NAPA number).

International U-6 Power Unit Carburetor problem

Anonymous-0

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teddy52food

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Haas

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