I need some help diagnosing my problem. Here goes I have a 19 kawai (FH601V) on a 52 TT, the engine is approaching 1400 hours. I just had it in for a valve adjustment, in which the tech performed a leak down test and a compression test. For compression he was showing 150 on the left hand side, and 125 on the right. He mentioned there should only be a 10% change between the two, but also said for the amount of hours the engine seems pretty strong yet. Today as well as the last couple weeks, I will be using this mower (primarily a backup) and it will run fine for an hour or two, sometimes even more, and then it will start acting up. It runs like it is not getting a spark, so it will suddenly die, then a second or two later it will fire again, and this process just repeats itself. If I let it sit and cool down then it will usually run for another lawn or two without any problems. This was really sporadic to start, and at first I thought it was because my air filter was getting too wet, I would switch too a new one and then it would be good to go again. Well today it finally seemed to kick the bucket, I could only get a bout ½ of run time on it and then the problems would start. I called the mechanic at my local shop and we started guessing what was wrong, at first he thought it was a coil, so I pulled the plug wire off one side at a time as the engine was running crummy expecting it to die, meaning it was only running on one once the bad coil heated up. This didnt do anything for me. Next we thought it might be electrical something which would be making that solenoid under the carb open and close if it wasnt getting a full 12 volts, so I went through all the wiring, everything looked okay there as well. I die-electric greased everything and put it back together to no avail. I checked all the safety switches as well. I also tried a brand new set of spark plugs. I seem to be getting strong spark when it runs Now I am out of ideas, so this is what I have done so far I ran another compression test on it when it was warm from use, and I was getting 120 on the left and 100 on the right. Does it make sense that the compression would be lower if the engine is warmed up?? How much compression do I need to keep it running? Next I took my timing gun and hooked it up, I noticed that as soon as the engine started sputtering the spark died, on both sides, neither one acts differently. Since I am fairly certain the coils are okay (see above) I am wondering what else may be the problem? It sure seems like a spark issue, is it possible the stator(s) have gone bad? Arent those kind of a permanent fixture on the flywheel? How about some suggestions from the experts? These engines arent that complex, what do you think the problem is? Since I have done this I cannot even get the engine to stay running, it will turn over and run for about 3-4 seconds and then die again. I am using this for my cleanups (only mower with a bagger) so when its out of commission its kind of a pain!