2.5Kv Onan Generator LP excessive consumption

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
K

Kbartus

New member
Joined
Jan 12, 2015
Posts
3
Location
Western NY
I have an Onan Generator (2.5HGJBB-1121A) that was supposed to be a direct replacement for the previous model of ONAN.
The Original Gen set was also a 2.5Kv LP generator.

The old generator I was getting a consumption rate of roughly 0.3gal/hr with less than half load.

Sadly the NEW (less than 6 months old) Generator is only giving me a consumption of 0.7gal/hr with NO LOAD.  The spec on this unit is 0.3gal/hr NO LOAD.  The consumption rate does not change when I put a 3/4 load on it.

This generator is used to run test equipment remotely in an enclosed trailer and I need it to run for 25hrs without refueling.  The trailer is setup with (2) 30# tanks which has given me 42hrs of run time on the older generator if I let it run to empty tanks.  We have a small AC unit (1500 watts starting/1200 watts running) and test equipment (350 watts)  The AC unit is only ran when outside temp are greater than 75 degrees and normally the thermostat shuts ac down in evening and load is much less.

Does anyone know of any adjustments on the ONAN genset to stop the motor from running as if it was under full load (That spec is 0.6gal/hr).

I have had the generator in the shop for this and no answers.
 
I don't know for sure, but there may a mixture adjustment.  FWIW - years ago, I had a pickup that was converted to LP.  I found that it seem to run equally well over a broad range of mixture adjustment and had been adjusted way too rich.  I leaned it out to the point it started to lose RPM, then backed it off a little.  I don't recall noticing any performance change, but the fuel consumption improved a lot.
 
I am dealing with the dealer since its under warranty.  I was going to ask them if there was a way to lean it out or would have to use some sort of a flow control on the propane feed line to manage it.
 
Kbartus said:
I am dealing with the dealer since its under warranty.  I was going to ask them if there was a way to lean it out or would have to use some sort of a flow control on the propane feed line to manage it.
Click to expand...
I would expect any "flow control" to be on the generator.  If there is no adjustment, it may have the wrong orifice in it.  Has the dealer conferred with Onan?  If he is just the RV dealer, he may not be familiar with LP generators and just shooting in the dark.
 
They initially found that the flexible hoses in the generator had pin holes in them......replaced them all.  I retested on a fresh tank and no difference in consumption.

I have talked to the dealer and they are going to contact Onan direct.  I have a good idea on how LP works BUT I am basing my knowledge off of gas small engines.  I am probably missing something but so far my common sense has been right.
 
You must log in or register to reply here.

Latest posts

Members online

Total: 872 (members: 6, guests: 866)

Forum statistics

Threads
131,973
Posts
1,388,457
Members
137,722
Latest member
RoyL57
Back
Top Bottom