I have a new (this year) Kohler SV620, 21 HP engine on my Hustler Fast Trak mower. Prior to this issue, I had zero problems with it. It runs great for quite some time and then starts running rough and loses power. I usually park it, wait and then fire it up again after a bit and it runs fine again. I swapped out the ignition module with no change. Carburetor untouched. Plug, connector and wire good, none loose. Fuel is good. Oil level and condition is good. I am thinking it has something to do with warming up to a certain temp and then the issue exposes itself. Electrical/sensor related. The engine itself is not overheating. Service manual cites the following potential causes:
Engine Runs But Misses
● Carburetor adjusted incorrectly.
● Engine overheated.
● Faulty spark plug(s).
● Ignition module(s) faulty or improperly gapped.
● Incorrect crankshaft position sensor air gap.
● Interlock switch is engaged or faulty.
● Loose wires or connections that intermittently ground ignition kill circuit.
● Quality of fuel (dirt, water, stale, mixture).
● Spark plug lead(s) disconnected.
● Spark plug lead boot loose on plug.
● Spark plug lead loose
Where is the interlock switch? How do I check it? Any other suggestions? Thank you.
Engine Runs But Misses
● Carburetor adjusted incorrectly.
● Engine overheated.
● Faulty spark plug(s).
● Ignition module(s) faulty or improperly gapped.
● Incorrect crankshaft position sensor air gap.
● Interlock switch is engaged or faulty.
● Loose wires or connections that intermittently ground ignition kill circuit.
● Quality of fuel (dirt, water, stale, mixture).
● Spark plug lead(s) disconnected.
● Spark plug lead boot loose on plug.
● Spark plug lead loose
Where is the interlock switch? How do I check it? Any other suggestions? Thank you.