Ive had Onans in RV's for yearsssssssss. I currently have a "Microquiet" 4000 KY Spec J which I just had to install a new "control board" at great expense to get it running grrrrrrrrrrr. I DONT LIKE THE MICRO"QUIET" what a misleading name grrrrrrr they are single cylinder so they have to scream n run wild at like 3600 NOISYYYYYYYYYYYYY RPM. Give me the old 2 cylinder 1800 RPM Emeralds anytime. HP is a function of Torque X RPM so with that single cylinder they have to get HP by running at more RPM grrrrrrrrrrrrr
PS many RV products utilize control boards which are built on like a printed circuit card and rebuilders like Dinosaur Electronics can furnish new or repaired ones wayyyyyyyyyyy less then what the manufacturers sell them for AND ALL I BOUGHT HAVE WORKED PERFECT AND LASTED. HOWEVER on the Onan Microquiet they are built in a heavy frame and its all potted (epoxy or whatever) and the rebuilders dont repair them and guess what !! You have to get them from Onan grrrrrrrrr $350 on Flea Bay and like $450 from an Onan dealer grrrrrrrrrrrr
Anywho, over many years Ive had ones that starve for gas but I was always able to remove the carb and clean them sufficiently to completely cure the problem yayyyyyyyyyyyy. I now always install a small inline fuel filter after the pump and before the carb.
MAINTENANCE NOTE:::::::: Its best to "exercise" them often cuz sitting for long periods isnt good on the carbs. At least once a month or even more often I start mine n let it run under a load and I have Sta Bil in the gas AND DOING ALL THAT SURE HELPS !!!!!!!!!!!!!!
To troubleshoot I have installed a temp fuel line direct from the pump stuck down in a can of gas to see if that cures the problem??????? If so I look for restrictions in the long line from the RV tank to the Onan. Ive also ran a gravity line direct to the carb to see if that cures the problem like a defective pump etc. As Im sure youre aware, the fuel line to the genny doesnt extend as deep into the RV tank so if youre much below 1/4 tank the genny doesnt get gas.
We dry camp a lot in Utah and Colorado and Arizona and Florida so the genny sure comes in handy and we use ours a lot, but if I had my druthers Id have the older 2 cylinder 1800 RPM unit verus the NOISY so called Micro"Quiet" YEAH RIGHT
Id love to hear an honest opinion of what the Onan service tech who posted thinks about the Microquiet? Am in the ONLY one who dont like them lol