kohler command 20hp on exmark TT is making an air sucking sound, like park plug loose

[clydesdale]

I seem to have full power, but there is a sucking sound that you can hear or a "chooch, chooch" sound at low rpm. It sounds as if air is escaping from the spark plug on the right cylinder, but the plug is tight. What should I look for? I thought exhaust leak, but I cannot find one and it sounds different. Any ideas?

[Phil G]

I seem to have full power, but there is a sucking sound that you can hear or a "chooch, chooch" sound at low rpm. It sounds as if air is escaping from the spark plug on the right cylinder, but the plug is tight. What should I look for? I thought exhaust leak, but I cannot find one and it sounds different. Any ideas?



Just a guess;
Slightly blowing head gasket;
Air filter
Breather valve.
Ignition timing.
Valve not seating.


Good luck, Phil

[viper00085]

head gasket or exhaust gaskets. Kohlers are known for both. Exh gaskets are a visually inspection, can do a leak down test to verify head gasket issue.

[clydesdale]

How hard is it to replace the headgasket and how soon do I need to address this? As of right now, it is just a sound and the motor performs fine.

[viper00085]

its not that bad of a job, just time consuming. Looking at removing exhaust, engine covers, intake manifold to get the head off.
If it is a head gasket, i would not run it long. with a blown head gasket the engine can run lean and hot, depending on where its blown, it could be forcing combustion pressures into the crankcase of the engine and cause oil seal blowouts and leaks, and oil use. also a blown head gasket can sometimes allow those hot exhaust/combustion gasses to act like a torch and cut a hole or slot right throught the block or head and kill a whole engine.

[clydesdale]

Will anything need to be re-timed or is this simple remove bolts, replace gasket and replace bolts. Will I need to time the motor? Thanks