Engine trouble/7117H

[Al]

My money is on Fred. I'm betting he nailed it. AL

[AdamF]

Gas is somehow getting into the oil. I changed the oil and put in fresh gas. Then adjusted the main fuel screw according to the manuel. (hasn't been running right). After i cranked it and no start,i checked the oil level and again had gas in the oil. Somebody said there may be a faulty switch somewhere but it sounds like major repair to me. Any help is appreciated.

[Fred]

Jeff, it sounds like your fuel pump has a bad diaphragm. That will put fuel into the crankcase, and is dangerous to the engine. Try a new pump.
Fred

[tej]

If it is a 7117 with a KT17 twin Kohler it has a fuel pump on top of the engine - follow the gas line from the carb. under the LH intake manifold. If it has dirt or water in the fuel (check carb bowl) do yourself a favor and clean out the entire fuel system from tank to carb - otherwise it could happen again. Try not to empty your container when putting gas in the tank - the debris will settle on the bottom and use a container with a good filter such as a fine screen. Don't forget to flush the oil again once the problem is repaired.

[tej]

Forgot to mention there's no fuel pump on this one. Somebody suggested it may be a stuck float valve.

[tej]

Yes there is a fuel pump and the problem could be either the pump diaphram or the needle and seat in the carb.When the problem is found and fixed why couldn't you just run the fuel; line through a good fuel filter and right into the carb, as this is a gravity type system on this model machine,the fuel pump really is not needed!

[Guest]

I stand corrected,there is a fuel pump. Me and a six pack are gonna have a talk with Mr.Tractor tonite. Thanks for the help.

[Al]

The big problem comes from vapor lock, these are tiny air bubbles that collect around the main jet and in hot weather and can act like a cork in the main jet causing an engine to die and them restart again when it cools down. These bubbles are sometimes responsible for gas being blocked at the needle and seat due to insufficient pressure to stop vaporization. On the KT series the pump and carb are right on top of all the heat. This is the main reason the companies went to fixed main jet carbs several years ago. These bubbles would collect between the needle and the jet. 1 then 2 then 3 or 4 and pretty soon the engine would die. It was due to the changes in fuel at that time. By going to a fixed main jet the hole was larger than the space between the needle and the jet and these small bubbles would flow on through. If the fuel is delivered under pressure to a hot area the tendency for the vaporizing is reduced. Same principle in a radiator the solution won't boil til 230 degrees under pressure. Six or seven years ago we were struggling with fuel problems and building carb heat shields etc. The engine mfrs. said the problems were spotty and sometimes just changing gas vendors would correct the problem. Warranty problems with newer engines that would run a half hr and quit etc, the recommendation was to put the fixed jet carb on. If the engine was blowing black smoke then heat shield the carb because the gas was boiling in the float bowl. Most of these systems are designed for a reason, and there several reasons for fuel pumps.
When I was a kid, in the forties V8 Fords had a real problem with vapor lock and you would see people along the roads on a hot day putting cool damp rags on the fuel pumps and fuel line to carb to get going again usually a sign that the fuel pump was getting weak again and time for a new one. My 18 cents worth and its free and you'll probably agree that, that is all its worth. Al