Onan 4000 surging at idle warmed up only
My Onan 4000 has developed surging at idle idle after warming up. If I apply a load, it smooths out. I did a change of air filter, oil and fuel filter. I also ran Seafoam mixture in 1 gallon can of...
Forum Discussion
dougrainer wrote:
Easy answer. Your Carb is gummed up. There are 16 VERY SMALL fuel jet holes and if just one is blocked will cause surge at idle. It is normal for a gummed Carb to smooth out under load or even increasing the idle speed. DO NOT INCREASE THE IDLE SPEED. Some do this and think they have fixed the problem. All it does is increase the output voltage. Doug
I read your post too late. I downloaded the service manual and adjusted the speed one full turn increasing voltage up to 122.5 with no load. I increased the sensitivity adjustment screw but put it back where I started. The surging is gone with or without load. However, while doing the adjustments and testing, I found that the Hz was fine with good load from AC, microwave or electric water heater. But when I have it only with converter charger with a high charging rate the Hz fluctuates between 45 and 62Hz. What's that all about? Happens only when converter charger is the only load on the generator. If I turn on anything else it settle down to 62Hx.
