Leakdown test shows no loss of pressure. Muffler removed and no obstructions. That leaves timing, coil, or something with the cam. Any common problems with this engine? Was well maintained.

Baymee, I'll just kind of blurt things out here for things to be aware of on these.You will get a sheared flywheel key from time to time. Another thing that happens is engine mount bolts thread up into the sump and can come loose. Harness and grounding issues are a result. Some are equipped with a choke wizard type thing that, rather than being a solid choke shaft- have a spring loaded shutter. When these break- it is normally a chugging rich condition- but would it flutter enough to change the engine noise? I've not had a cam issue on these unless due to the ACR. I have had ignition coils that will throw the spark at the wrong time. In this case, you need to be aware if you have the SAM on this beast.

A red hot muffler "typically" indicates a lean fuel/air ratio or retarded ignition timing.

Running at "high or low speed well" under a NO LOAD condition doesn't really indicate much except that it has enough power to overcome internal engine friction.

Lean condition on Kohler comes from throttle shaft being lose allowing air to enter. Link below pdf so pick kit number needed.

Here is a link that might be useful: Throttle shaft repair kits

heh heh

I had a few minutes before a picnic yesterday and I pulled the shroud off the top and it appeared that the key was sheared. Sure enough, it was.

I remember the guy saying that it got worse and worse until he couldn't cut the grass anymore with it.

Thanks for the tips.

Do you know the torque on the flywheel bolt?

With the tapers clean, and when the flywheel nut or bolt is tightened or torqued to specs, the "squeezing" action of the flywheel taper actually "grips" it to the crankshaft, guaranteeing positive metal to metal contact, with no slip whatsoever. Torque the 15/16" nut to 65 ft. lb., and the 3/8" bolt to 35 ft. lb., but do not overtorque it! (As with an air impact wrench.) And Kohler's flywheel [castle] nut is self tightening. Therefore, a lockwasher isn't necessary. But sometimes the nut will wear and tend to loosen over time. When this happens, the flywheel could loosen, and the keyway in both the flywheel and crankshaft will become damaged beyond repair. Therefore, a new self-tightening jam nut is required for a professional repair. But use a split lockwasher on the bolt. And use a grade 8 bolt, nothing less.

Here is a link that might be useful: flywheel nut

It's a bolt. Thanks to all.

have troy bult lawnmower with 22 kohler engine when i go up a slight grade i get white smoke out the exhaust. what cause this

Blown head gasket

My Kohler SV 740 begain running intermittently on the lleft cylinder first, then finally failed. A few days later while troubleshooting, running on one cylinder, the right cylinder failed. Checking for ignition, i had no spark at all on either cylinder. Thought it might be coils, although unlikely that both would fail together. Purchased replacement coils (CDI) installed, gapped at .010, still no spark. Tried 3 other gap settings, no spark. Checked kill wire, other links, etc. All OK. Is it possible that the flywheel magnet is at fault ? Rare I guess, but is it possible ?
Any thoughts ?

I have a Troy Bilt 22hp xp horse riding mower with a sv620 Kohler motor. It won't stay running after 10 minutes. I believe it's a problem with the fuel pump but , it doesn't appear that it came with a fuel pump ! Am I missing something ?

Sounds like you are missing a fuel pump.

wild- you really should start a new thread w/ the complete tractor model from below the seat and the 4 digit number that comes after the one given. Quick things to check are that the vent in the fuel cap is unobstructed and that the proper fuel filter has been installed. I've also seen my share on sticking anti backfire solenoids which can create issues if they are stuck in the not quite closed position.

tomplum, Thanks. sounds like good advice. I'll start there. Wildwillie68

I have a question. Finished mowing and washed down mower. later went to put itupand it was runningveryy rough. 2 days later tried to start and It wouldn't turn over. Bought a new battery but it would turn just a little then drag some. Had also replaced plug. I pulled the plug and the motor would spin when the i hit the starter. Replaced the plug and once again it would not spin. Like it had too much compression.

I have a 19 HP Kohler SV 590...motor starts and runs really smooth for 2 or 3 minutes, then runs really rough, kinda lopes, then dies. I've changed the fuel filter, fuel lines, and thoroughly cleaned the carb..no help...any ideas...???

same thing Tom referred to above... fuel filter. Kohlers are most finicky about requiring the correct OEM fuel filter. If you have installed an aftermarket, watch out.

If not that, would ask details of your carb cleaning procedure....