25hp Kohler/Fouling plug

[muxx]

I have a 25hp Kohler that has had new rings and a vavle job done. It is still fouling out plugs on the left side. Any ideas? Had a new valve put in on that side, not sure if anything else. Thanks for any help.

[Jusmowin]

cheap way first: replace plug wires and coil, and while your at it do the other side also? Make sure clean up really good!

[sanman]

Did you do a compression test? Or a leakdown? Even though the rings / valves were done, I'd still verify cylinder sealing. Do you know if the valves / seats were reground, or just lapped? Also, if you could post a pic of the plug, it would be helpful.

Al.