> I just picked up a swap meet special, a small Coleman
> generator of 5.5 HP size, capable according to the ID plate
> of producing 2250 watts.
>
> It runs and will drive small electrical loads (only brief
> field tests so far) but needs some attention, probably
> carburetor work and the engine puffs a little smoke, so
> maybe rings are needed. A nice little B&S engine, so parts
> should be available.
>
> What is it that determines the correct Hz? Is it the
> mechanical governor on the engine?
Most small gen sets have the frequency determined by the engine rpm. Don't
expect it to be right on the money, +/- 5% is a common spec and many small
units are only good to +/- 10%.
> Any advice as to how to
> adjust it?
Get it running just right first. Decoke the heads, adjust the valve
clearances, clean/change the points, set the mixture, etc. Then most likely
you'll find some sort of length adjustment in the link between the governor
mechanism and the throttle. Use this to set the frequency to roughly 60 Hz
under full or maybe 80% load. (Electric space heaters, combined with a few
100 watt lamps, make good dummy loads.)
> I never had the opportunity to learn much about these little
> generators, and have no understanding of how they are
> regulated for consistent output.
There will probably be something to regulate the output voltage, by
adjusting the DC voltage to the rotor windings. But the frequency is set by
shaft rpm. "Consistent" is not exactly how I would describe it, but most of
the things you're likely to run aren't real picky about frequency and
voltage. Just don't expect your electric clock to keep time <G>
Randall
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