I have a 186FA on a 5000W/6500W surge generator that I am having speed control issues with. I put in a new injector, having previously replaced the fuel pump. (Old fuel pump leaked around the fuel intake.) I put on a new air filter as well, and I changed the oil while I was at it (filter was spotless).
This morning, I ran a load test of 4500W for 45 minutes or so. Air temp 60F. Light smoke from the exhaust the whole time, getting slowly less as time went on. The exhaust smelled fully combusted, unlike the old injector when the exhaust smelled like diesel. The engine held speed under load, the governor functioned normally. On target voltage and frequency. I will say that engine exhaust got HOT. The muffler turned from black to a grey and the little label on the frame over the muffler warning of the hot exhaust slowly got baked black. Then again, I have never really pushed the generator before. The generator has forty eight hours of use, mostly light duty backing up the house during power outages, where the microwave and the 3/4HP booster pump are the biggest load it sees. So, yes, probably lightly loaded for much of the forty odd hours.
The problem: after I took the load off and was letting the engine run to cool down, I heard the speed drop, and noticed that the governor was pinned against the high fuel limiter. I added back load and the engine came back up to speed, the governor came off of the limit pin. I then cut the load again, and the speed dropped. Just for grins, I tried adjusting the speed downward a few hundred rpms, which brought the governor off the limit pin for a minute or so, and then pinned.
I am stumped. Any ideas?
All the best,
Peter
