loupoin

I was hoping to see a more replies as I have the same problem and model (but it's my neighbor's mower- I'm just trying to help the mechanically declined). He's had it in storage 2 years (he did run out the gas before storing). I charged the battery, removed and cleaned the carb and air filter, replaced fuel line (it was cracking), and put in fresh fuel. After re-assembly, it started on the first crank but was loping, or surging. It runs fine at full throttle under load but surges at anything less (but does not die out- like yours). After reading a lot of posts here, I going to now check 1) fuel cap vent, 2) plug and gap (again), and 3), governor and carb linkage (again). My neighbor thinks he remembers it doing this just before he stored it (ahh haa, maybe not storage related).

My thoughts... FWIW! My first thought was the limited fuel/air mixture screw. When I cleaned the carb, I noticed most of it is plastic including the jets. I guess 5 years of use could wear away plastic, so it could be running a little rich. The limited range of the low speed fuel/air mixture screw did nothing for the surging and the low idle adjust dscrew did nothing when I adjusted it from fully closed to fully open, huh?! And the tension spring on the governor linkage connects to nothing but itself. The end toward the carb is mounted in the linkage hole and the other end mounts on the governor arm coming out of the engine less than an 1/8" from the linkage. It effectively has NO tension on the spring. When I use a finger to buffer the governor, the mower runs smoother, but still surges. To me it seems it should be mounted to a fixed location. If anything gives, I'll let you know. If anyone has words of wisdow or advice, please let them flow.