I have a Coleman Powermate 5000W generator with a 10 HP Briggs and Stratton motor. When using the generator the typical load is 1KW to 2KW, the Powermate has an output of ~147 VAC and 74 to 75 Hz. The RPM's are extremely fast (don't know what speed but they are high).

When I introduce an additional 1.5 KW load (little space heater), making the overall load 3 to 3.5 KW the generator RPMs and output is steady and dead on 116 VAC to 120 VAC and 59 Hz to 60 Hz.

What can be done to make this generator output a steady 120 VAC and 60 Hz regardless of the overall load???

Don't want to run a heater in the summer to just have a steady output from the generator. Plus, with a large load such as 3.5 KW fuel consumption will be higher, too...

 

what is no load like re rpm ,voltage ,hertz?

 

About the same, if not a little higher...Maybe 150 VAC and 75 to 80 Hz...It fluctuates until I get the 3 to 3.5 KW load on it...

 

The rpms should be pretty much the same, light load or full load. Sounds like a governor issue.

 

If it is the governor, how do I adjust it to make the generator run "normally"?

 

Have you ever had the carb off and possible got the linkage wrong. Can't put my hands on it right now but I have seen the adjustment for it . Might be in a briggs manual. Might be as simple as an adjusting screw. Start by getting the right hertz at no load.

Ok ,
Found this in briggs L-head manual 270962. Can't copy images as it's a PDF
Adjusting Top No Load Speed
Generator Applications
1. Run engine at half throttle for five minutes to bring
to operating temperature.
2. Move speed control lever to maximum RPM
position.
3. If tab on lever is touching head of TOP NO LOAD
RPM adjusting screw (2), back out screw until tab
no longer touches screw when control lever is in
maximum RPM position, Fig. 23.
4. Bend spring anchor tang (1) using Tang Bender-
Tool #19229 (4), to 3300 for 50 cycle or 3800 for
60 cycle.
5. Turn TOP NO LOAD RPM screw clockwise until
3150 RPM, 50 Cycle or 3750 RPM, 60 Cycles is
obtained, no load.
NOTE:If available, use a load bank to load engine
to full generator rated output. With
generator at full rate output, turn screw to
obtain 3000 RPM, 50 Cycle or 3600 RPM,
60 Cycle.

 

Generally, the governor should never have to be changed after the engine leaves the factory. Speed issues are usually caused by something else, like a sticking throttle shaft or linkage problems.