Engine Craftsman Kohler Command CV20S surges & backfires

[letterpressman]

I hope to solve my problems here. I've been reading the thread list for a week looking for similar problems with solutions. Close but not quite. No pictures, it's just a garden tractor. It's a Craftsman Kohler Command CV20S garden tractor(917.273022) with a 46" 3 blade deck that clogs with grass and gives a rotten cut unless I keep the deck clean. It baggs leaves real well. I bought the display model in '99 with a 3 bin bagger and added a box grader to excavate the patio a few years back. I also added a ball hitch to pull a 6x8 box trailer around the yard to collect leave, grass and garden waste. It's been a real workhorse until last week when it started on only 1 cylinder. It appears that something has been chewing my wires. A neighbor fellow helped me diagnose the problem. We took the top shroud off the engine and 1 plug wire was hanging by a thread. Also a purple wire in the harness was stripped bare about 4 inches in the middle of the wire. one week and $70 later, I replaced the coil w/plug wire and taped up the bare wire. when I put it all back together, I find my friend removed a 3-4 inch black wire with a screw lead on both ends and a machine screw in one end the same type of screw that hold on the shroud. For the life of me, I can't figure where it came from or what it does. The engine runs on both cylinders. With no load the engine surges every 2-3-seconds(not much worse than before) and backfires out the muffler a lot! Could the mystery wire be the culprit? All the exploded views I found online are no help at all. As long as I'm moving and mowing, no problems. Any suggestions? I'll repost this as a new thread in hopes of finding an answer. Thanks.

 

[Rivets]

I'll bet your black wire is a ground wire. Can't really tell you from where as I don't know all the parts you removed.

 

[ILENGINE]

I suspect that black wire is the grounding lead for the voltage regulator. On some engines there is a wire between one of the plastic cover mounting screws, and one of the screws that attach the voltage regulator to the plastic cover. Won't charge without it. The other possible location is between the carb, one of the four top screws holding a cover on the carb, and a metal part of the engine to ground the fuel shutoff solenoid

You said that one end had a shroud cover screw in it. If that screw has a gold color, then it is the regulator grounding wire. Newer models have a metal strap instead of the wire.

 

[Rivets]

I agree, as usual ILengine has you on the right track. I should have thought of that. My brain has been a little foggy lately, and I appreciate IL's setting me straight. Thanks.

 

[Fish]

Post your engine's model and spec numbers. Craftsman loved to use Smart spark.......

 

[letterpressman]

The plate on the engine says: Family-SKH624U1G2RB
Model -CV20S
Disp.(cc)-624
That's all.
My consultant is not returning my call so I will try the ground to the regulator. That looks about right. When I took it apart the 1st time, I removed as little as possible so I didn't have to remember where it came from. I unplugged the regulator rather than removing more screws. I hope it charges.

As far as the surging and backfire, any guesses? Just a dirty carb. or is there a way to adjust the timing?

Thanks guys, I appreciate the advise.

 

[reynoldston]

Have you just tried a carburetor adjustment?