Kohler Command 40 acting strange

[BLES]

Trying to figure out a strange one for my neighbor...
Kohler CH1000-0010

Started running poorly. Sound got VERY loud from the outlet of the muffler (not a hole). Sounds like a LOUD Harley, even when it's just running slow. Sounds like the engine is really laboring hard but nothing is engaged. Muffler appears in very good shape and the loudness just started when the other symptoms started. It IS running on both cylinders, but is down on power. Compression was about 150 on both.

It had a chunk of ice in it let loose and break the fan and damage a coil, so both coils were replaced (#62-584-17-S).

Any ideas at all? Thanks.
BLES

[bgsengine]

Sheared flywheel key throwing off the ignition timing would be my first guess.

[BLES]

[quote=Sheared flywheel key throwing off the ignition timing would be my first guess.[/quote]

Timing was also my first thought, although I didn't think it was "adjustable". That's why I first checked coils. Never thought of a flywheel just "slightly" moved from shearing. Anyway, it's not that. However, I found stator and flywheel has been replaced. Flywheel has 62-300-02 part number cast into it, but I think current part number listed is 62-025-05-S. Is it possible it has an incorrect flywheel?

I have what appears to be an identical flywheel off a CH980-2014 that also has 62-300-02 cast in it. Current part number listed for that is 62-025-03-S.

Thoughts? I appreciate your ideas and insight.

BLES

[BLES]

OK... I found 3 of these flywheels with the same casting number, but the keyway is different on one of them. SO, I think I'm going to try that flywheel and see how it runs. If it's good, that means someone installed the wrong flywheel when they changed it with stator. Possibly makes sense... I just don't know why they didn't realize the problem then and tell me this.

BLES

[KE4AVB]

Note that the 62 025 03-S is discontinued so hang on to it.

[BLES]

Thanks guys. I appreciate your input and advice.

I swapped flywheels and it runs fine. I long for the days when people tell you the whole story upfront!

Just fortunate I happened to have another one. Not sure what I even saved it off. Don't do much of this stuff anymore. And, I now have two of the 62 025 03-S now. The other one must have been the other part number.

BLES

[KE4AVB]

I hate it when I have undo someone screw up just to get to the real problem. And those guys are always trying to get me to make financially whole again. Not going to happen as I actually have to bill more as I have to redo their screw ups first.

As you just found out you just can't go by the casing numbers as there about 30-35 different flywheels with the same casing number.