Toro Mower Misfire
I have a five year old Toro 200017 mower with a Tecumseh LV195EA engine.
The engine developed a miss a while back. Eventually it quit running while my wife was using it on a hot day in thick grass. When I got home I was able to get it running but it surged a lot and still wanted to stall if I didnÂt baby it.
So far I have:
Drained the fuel tank and replaced and ran new fuel through it.
Checked the fuel cap vent.
Check the flywheel/shaft key, it is perfect
Replaced the spark plug
Replaced the coil/plug wire assembly that is referred to as the "lamination" in the parts list
Pulled the carburetor and blew out all the passages with carb spray and replaced the bowl gaskets, needle and seat.
The kit didnÂt include the Carburetor to manifold gasket but the existing one looked fine.
Replaced the fuel line just because I had it off.
It no longer surges and I mowed for about 30 minutes today with no stalling. There is still a consistent miss. It occurs almost every two to three seconds, is usually a single stutter, and from time to time can be two or three in a row.
Having eliminated the ignition system (I think) my guess is that there is a lean mixture problem. I was spraying carb cleaner around the carb with it running and when I spray right where the throttle shaft penetrates the top of the carb the engine will miss pretty seriously. It seems like there is a leak around that shaft and hitting it with the carb cleaner is changing the mixture, causing it to miss fire.
Does this make sense to anyone? Usually finding a leak with spray will cause a momentary surge in speed.
Am I missing something else I should check?