Hey guys hope you can help...kinda desperate here having issues with my money maker.
I have been in lawn care for over 30 yrs and ive never had one act like this.
I have a cub a rzts 46 cub cadet with a 24 kohler on it KT735-3013. This started a few weeks ago. When it runs it flubbers like a plug trying to foul or a valve sticking. But it just does it for a few seconds then returns to normal. It does it at any time, but does it evrytime you turn the blades on or put it under a little load driving. But then it recovers for 15sec to however long some, times it wont do it for a few minutes.
It also has a leak around the muffler gasket on one side. When you move the throttle up and down it will backfire.
This is what ive done. Changed the plugs when it first started doing this. Ran the motor with an inline spark checker. Plugs didn't help and spark seemed good. I also put MMO in the fuel and oil. No help.
Cleaned the carb several times and the whole fuel system. No help. Shortly before this started happening I put an inline fuel shutoff on. I have concerns this is restricting my flow. But it does it at startup so I wouldn't think the bowl would be low enough then. Tested fuel pump also.
I have noticed on one valve cover where it looks white hot and trying to rust, right over the exhaust valve. I took off the valve covers and everything looked to be moving normal. I put them back and cleaned the carb again seemed like it helped a little. Now I have them off again, a local mechanic swears that I have a bad head gasket and the leak im hearing around the muffler area is not the exhaust gasket but the head gasket. I did a compression test and I got 165 on the other side 120 on this side. The other side seems fine. This side has low compression, burnt spot on the valve cover, and is puffing around the muffler connection. The intake valve is set at 2 or 3 thousands and my exhaust is at .005.
Whats you guys opinion???? Any help is greatly appreciated.