to test the ignition, use some duct tape to rig the spark plug wire about 3/16 inch away from the engine cylinder head. With an observer and a darken garage, hold the bail and pull the cord. If there is no spark, remove one coil bolt to clean the rust under the bolt head. INSTALL and tighten the first bolt before removing the second bolt for rust removal. Reply with results. Usually, non starting problems are related to old residual fuel that is still in the carburetor. The fuel primer on this engine often fails after 7 - 8 years and carburetor work is required.

If I understand, there were two problems: (1) fuel leaked through the carburetor and contaminated the oil - this was fixed by overhauling the carburetor and changing the engine oil. (2) it makes a kind of popping and misses except on 2nd gear. This is the remaining problem. I am trying to understand your description. Here is another thought. This is a high mileage engine. Perhaps there is an accumulation of carbon in the cylinder. This is a flathead engine. Consider pulling the cylinder head to clean the out the carbon. Also check the valve clearance.

A good way to approach this is to remove the air filter and give a 2 second burst of carb spray into the carb, crank it and see if it wants to run. If this adds nothing to the mix, for testing purposes- you could remove the kill wire that goes under the engine shroud to the small terminal of the coil. Try these things and post back. Most of these had Tecumseh engines. Which engine it has would be good to know. You could actually reverse this process and check and see if the kill wire removal helps first- in case that it may be flooded at this point.

Update today, hoping you guys can suggest whether this new problem is also the carburetor or if I need to replace yet something else :-/ Today was the first chance I've had to mow since my last post... tons of personal problems in the last month, each day progressively worse than the last. So I wasn't at all surprised to have a new one today. I was about 2/3 of the way down with mowing the back yard, with the throttle at about halfway. I had the speed level on 1 because the grass is high and just a little wet. It suddenly shuddered a little and had a flapping sound underneath, so I thought that it must have picked up a long weed or something in the blades (pretty common in my yard). I hit the brakes, then the engine started to die. Before I could disengage the blades, though, the engine picked back up and the flapping stopped. I didn't see anything shoot out, so I assumed that whatever it picked up must have been chopped in to little pieces. That whole thing was probably 2 seconds. So I let it run for a few seconds with the brakes on, then start back to mowing. Within a few seconds, the throttle goes SUPER high! There aren't actual numbers on the throttle, but for the sake of discussion let's say that all the way down is 1, all the way up is 10, and Choke is 11... I had it on 6, but it felt like it was at 11! I pushed the throttle down to 1, and nothing changed. At this point I thought the engine might blow, so I put the speed up to 3 so I could hurry and get it to the shed. But at that level the throttle dialed back a little, so I continued mowing at this higher speed. When I was done I disengaged the blades, and then the engine throttle skyrocketed to 15! So I turned it off and pushed it out of the yard. It was obviously getting a LOT more gas than it was supposed to. Looking underneath, I can see that when I move the throttle the spring still catches and moves the lever. I'm not sure what happens after that, though, it's kind of behind a piece of metal. What do you think... still a problem with the carburetor, or am I know having a whole new problem? If you can't tell based on this, can you suggest what I should look at to narrow it down? After replacing the blades and everything last year, then the gas tank this year, and now the carburetor... I'm starting to wonder if I'm throwing good money after bad :-(