Re: Derating for propane
Some notes on generator conversion derating:
If engine horsepower and generator output were matched, any changes that would affect engine hp would reduce generator output.
Dual fuel conversions add an extra venturi before the carburator, which restricts airflow somewhat, a resulting 10% power loss is a reasonable estimate. this power loss would be the same on a converted engine even when using gasoline fuel.
I have the Yamaha EF2400, with a 5.5 hp engine (the same engine powers the 2800 and 3000)
5.5 hp is about the equivalent to about 4.1 kW, significantly more then the 2.4 kW rated maximum output. Subtract about 20% for generating ineffiency and you still have about 3.3 kW of output energy available.
Take away another 10% for the propane conversion power loss and you still have a 2.97 kW potential.
Now, if you go camping at in the mountains at 7,000' subtract another 15% for the reduced atmospheric pressure and you still have over 2.5 kW available engine power.
It's reasonable to assume that you can get full generator output from a propane converted Yamaha EF2400 under normal operating conditions.