Not the most tech savvy guy here...I am better at computers than power equipment...just so you know the level of expertise involved.

But I searched some keywords on your site and think I have nailed down some of the problems with an old tractor I have. I spent the morning in search mode as I had seen that reccomended in other posts more than once.

Tractor is a Cub Cadet 129. Kohler engine with the original carberator from about 35(?) years ago. The engine was replaced with a 'short block' a few years back. K301 is the designation on the engine and I believe it is 12 HP. Gas tank is above the engine so I take it to be gravity fed fuel (I see no pump...) It has been a beast of a machine for me for about 18 years (they don't build them like this anymore, do they?)

Anyways, the problem is that I found a fuel leak. Removed the air filter and found the bottom part of it was wet and that gas was leaking out through the throat(?) of the carb (past the choke 'butterfly'). I found the fuel shut off on the tank and fixed it for the moment. I went back and drained the tank (It was surprisingly clean--no debris). I already plan to replace the fuel line and add a newer in-line shut off as the original tank shut off is not quite perfect at stopping the flow of fuel. It might be redundant but I don't want to mess with the tank fittings and end up with another problem. There was no gas smell to the oil. Oil level was at full (but I am due a change anyways so I'll change it when I resolve the problems).

The fuel problem (SHOULD) be a stuck float or debris in the carb bowl and/or small openings inside the carberator. (from what I've read this AM) I plan to take that apart and use some cleaner liberally.

1) Any tips or advice for that job on this particular engine?

2) I've noticed a 'greasy' black residue in the carberator that did wipe off with a rag but did not respond well to the carb and choke cleaner aerosol I tried (this was visible inside the air filter on the outside of the carberator. (I have yet to get inside the carb...) Any Idea on what this might indicate? Fuel mixture is off perhaps??? I can see the screws to adjust it but I'd need a step-by-step in order to attempt tweaking them. I have done this successfully in the past with 2-cycle stuff that was worth little enough that I was willing to tinker with it before tossing it out ...so I have a general idea...

3) I have a borrowed compression gauge and would like to know what it is supposed to have for compression--seems like a good thing to check while I am tinkering away. Anyone know that PSI? Or are all engines the same (somehow I doubt that)?

Thanks for any help offered. Some of you guys certainly know your way around small engines and I have to admit some tech-envy...

Dave