My portable welder has a 12 HP Kohler that went to a slow idle while I was welding. When I checked the point gap, it had closed to .011, so I opened them to .020 and it wouldn't run at all. So I replaced the points and condenser. Now it will run fine for 15 seconds and die. I took the carburetor off to check the float, but I can't tell how to remove the bowl. When I took the 1/2" hex cap screw off the bottom I could see a brass adjustment screw deep in the threaded hole, but I couldn't turn it. Neither of these seem to hold the bowl in place, though, and there are no screws around the rim of the bowl. Any ideas?

how old is it, the bowls can get stuck on pretty tight. that screw way up there was just a jet, it stays there like that tight, if there was no screw on the bowl nut, then there is no adjustments there

This is an old cast iron engine, Model K301S. It uses a lot of fuel, but it always ran great. I guess this is a disposable carb.

not sure on that old of a engine, but that carb shouldn't be disposable, but if its got alot of use its probablly time for a rebuild, and if there is no rebuild then you may luck up and find a new one.

Anyone know the standard carb adjustment for an older Kohler mounted on a IH Cadet riding lwn mower?

I guess to clarify it better, what I am referring to is the standard starting point for the main jet after a carb has been cleaned out. Ones I have worked with before usually start on about 13/4 turns but his one won't keep running at that poin so I can fine tune it.
any suggestions appreciated. I am doing this to help an older lady who lives out in the country.

Thanks for your words of encouragement. I found a website out of Columbia, Missouri that sells the parts I'll need to rebuild the carb. It's going to take more than a standard kit. I've drilled out the brass main jet the goes down the center of the bowl. I think I can do all this cheaper than buying a rebuilt carb.

you drilled out the brass main jet , i dont think i have ever done that

My portable welder has a 12 HP Kohler that went to a slow idle while I was welding. When I checked the point gap, it had closed to .011, so I opened them to .020 and it wouldn't run at all. So I replaced the points and condenser. Now it will run fine for 15 seconds and die. I took the carburetor off to check the float, but I can't tell how to remove the bowl. When I took the 1/2" hex cap screw off the bottom I could see a brass adjustment screw deep in the threaded hole, but I couldn't turn it. Neither of these seem to hold the bowl in place, though, and there are no screws around the rim of the bowl. Any ideas?
Some hints: Does fuel tank have a shut-off valve? With the nut (drain plug) out of the bottom of carb, turn on the fuel valve...does fuel run out of the bottom of the carb? It should run out enough to fill up a tablespoon in just a few seconds.(by the way-observe all safety precautions when spilling gas about)
If fuel flow is good-proceed>
Tap(gently-wood or plastic tool) on the carb bowl- it should break free (and probably destroy the bowl gasket too) Whats it look like on the bottom of the bowl? rusty?dirty? You can now also get a better look at the inside of carb..crusty/corroded? Remove the small shaft that the float pivots on and remove float and needle. Needle valve clean? shake the float-does it have any fuel inside it?
Unscrew the main jet(usually points up from bottom of carb)Clean everything(carb cleaner in a spray can works well) and put it back together. Then pray to the carburetor god & hopefully you will be back in business. Or at least you can get an idea of what parts you will need to rebuild carb.

I did rebuild the carburetor successfully. The engine now runs very well for 15 minutes, then slows down and cuts out. I have decided to change the ignition coil if I can find one to replace it.

yeah, that could be failing under heat

I got the name of M and D Mower off of somebody's reply on this message board and used it to order the ignition coil I needed for my 12 HP Kohler. This was on May 17. Their webpage didn't show any order from me on May 19 when I tried to track the order. So I called and was told they have the info. and would email my tracking number later in the day. I didn't hear from them so May 20 I called and they said the order was placed on May 19. Apparantly they dropped the ball and won't admit it.