Kohler K321 misses firing
Posted: Sat Jul 08, 2023 7:00 pm
This engine was running fine after replacing the bent exhaust valve. Went to mow the lawn the other day and it started to run worse and worse. Seemed fine at low RPM, but as opening the throttle would clearly miss firing at times. Here's what the firing miss sounds like:
https://vimeo.com/843024319
Something interesting: I hooked an ignition light in between the spark plug and coil and it shows a fat strong light only when I hear the engine detonating properly. When the engine misses the light is weak to none.
By the time I shot this video above I have done the following:
* replaced the carb with the one from the 444 which runs great
* tried a few different spark plugs, spark plug wires, condenser, and ignition coils
* replaced the points with new ones, and adjusted
So nothing fixed the problem.
Fearing the worst I took the head off again. It show zero evidence of blow by the gasket. Valves seem to be fine. I checked the points closing with the multimeter, while turning the engine by hand. Basically if it shows 1 then the points are open, when it changes from 1 it shows continuity, meaning the points touch. What do you guys think?
https://vimeo.com/843545047
The valves don't seem to be stuck at all. I have not yet checked the valve clearance.
https://vimeo.com/843024319
Something interesting: I hooked an ignition light in between the spark plug and coil and it shows a fat strong light only when I hear the engine detonating properly. When the engine misses the light is weak to none.
By the time I shot this video above I have done the following:
* replaced the carb with the one from the 444 which runs great
* tried a few different spark plugs, spark plug wires, condenser, and ignition coils
* replaced the points with new ones, and adjusted
So nothing fixed the problem.
Fearing the worst I took the head off again. It show zero evidence of blow by the gasket. Valves seem to be fine. I checked the points closing with the multimeter, while turning the engine by hand. Basically if it shows 1 then the points are open, when it changes from 1 it shows continuity, meaning the points touch. What do you guys think?
https://vimeo.com/843545047
The valves don't seem to be stuck at all. I have not yet checked the valve clearance.