What Cummins Onan Generator Can I Replace the Model 4KYFA26100K SERIAL K030571438 With?  

Question:

Expert Reply:

Hi Wayne,

To replace the generator on your customer's horse trailer, I recommend going with the Cummins Quiet Series 4000 EVAP Onboard RV Generator Part # CM32ZR. The # CM32ZR is rated for the same 4,000 watts, 120V, and runs on gasoline only. The size of the generator, mounting bolt patterns, and exhaust configuration should also match; making this a great option because it'll require little modification.

Cummins has mostly phased out the non-EVAP models of generators, but since this generator is an EVAP you can cap or plug the EVAP port on the generator if the trailer doesn't support this set up. The safest method though, would be to add a short length of fuel-rated hose to the EVAP purge port, add a breather filter, and inline fuel filter or breather cap at the open end of the hose. Make sure the hose points down to vent out the bottom of the generator compartment into open air and is away from anything hot like the exhaust.

What devices do they run with the generator?

expert reply by: Claire H

0

Wayne H.

9/8/2026

The heaviest load is a roof air unit. Otherwise lights and a water pump.

Claire H.

9/8/2026

@WayneH Gotcha, it should easily be able to handle that amount of load. Since it's the same wattage as his previous generator, I'd expect it to run those appliances the same amount of time as the old generator.