Kohler K301 Question

[SteveP]

Been playing with my AC712 and have a concern with the Kohler K301. Sitting still at full throttle it sounds pretty good but when I drive the motor starts “Hamming” like rod knock C. Can’t find anything external loose (yet), like muffler etc. I’ve have it my mind that’s timing but can’t find anything in the manuals on how (or even IF) the timing is check/adjusted. 8 Someone before I aquired this wrote "Rebuilt 8-13-93" on top of the K301 and seems to have adequate power however I have only drove it around (no attachment at this point). I really doubt that “Hammering” is a normal sound for these old Kohler, Right ? Do these benefit from removing the head and cleaning out the carbon like Briggs ?

[HubbardRA]

Steve, I didn't answer earlier, because I am not very knowledgeble on this subject. I think there is a hole in the plate between the flywheel and the block. This is near the corner where this plate meets the air shroud. I am not sure, but it may be below the starter. I am going totally from memory from when my friend did tractor pulling with a pro-stock garden tractor. I think he also said the flywheel had a mark on it that should line up with that hole when the timing was right. The only way to adjust the timing is by varying the point gap, which is normally spec'd at .020. If it is "pinging" then you should try closing the points just a few thousanths. Drop the gap back to o.o16 and try it. I would definitely remove the head and check. Carbon in the combustion chamber raises the compression. High compression causes pinging the same as fast ignition timing, in fact they play together in that extent. Good thing is that if you are careful you can remove the head, clean the piston and head and replace the head and re-use the head gasket. I have done this many times with no problems. Make sure the gasket is clean and there is no carbon or oil in any of the little dimples on the gasket. Be sure it lines up with the block and head like it came off. Torque the head bolts to the correct amount and in the correct sequence.

[PeppyDan]

I know the sound you're describing. It seems very common on only the 12hp Kohler engine. I had a friend rebuild a 12hp (piston, rings, bore job, gaskets, and new bearings)for the leveling drag tractor that our pulling club used and it still "hammered" as bad as before the rebuild. He pulled the engine back apart to make sure everything was installed correctly which it was. We just learned to ignore the noise. I am currently rebuilding a K301 and am concerned with the same problem(I have never heard this engine run)and noticed the counterbalance gears seem to show a lot of wear on the gear faces. I plan to reassemble the engine without these gears since it appears that some Kohlers did not have them in and have heard of other people removing them with good luck. I posted a question about removing the gears a month or two ago and got very little response about it. I would also like to make the engine sound like it's not about to fly apart. Dan