I need some help, my generator is putting out 151 volts. Could it be a voltage regulator?


Finding parts for thes old generators are hard, does anybody know a good resource to give me.

 

I use this place in Houston. They will talk to you and help you figure it out as best they can with not seeing it.

www.pplmotorhomes.com

Then Precision Equipment has a forum here www.perr.com it's not just Onan though.

 

i would check engine rpm. i had a 240 volt that was doing over 300. engine speed was way over spec.

 

^ Yup! Engine speed is directly related to Voltage and HZ.

 

YEP, correct. Check the frequency and slow it down to 60 and the voltage will probably be right on. Look for the small lever, held by a spring, that you can move and change the rpms. It will have an adjustment screw. Put your voltmeter on the output and slow that sucker down by adjusting the screw until the voltage reads 120 - - you will probably be right on 60 hertz.

Bob

 

Cool!!! It can't be that simple for me. It usually means spend a thousand $$$ and rebuild it etc. etc.

Thanks guys, I knew ya'll would know

 

Also, what oil should I use in this Onan 4.0 CCK?

Thanks

 

I have several that I maintain in a fleet and we put 15w40 in everything. Including the Onan generators.

 

Set it between 58 and 62 Hz. you can use a good DVM that counts frequency or the simplest way is to plug in an old synchronous clock the kind with hands and a motor, when the minuet hand goes around once and it the same as your digital watch the frequency is at 60 Hz and the engine is at 1800 RPM.

Check out this other site I am on, it is all about generators and old iron, there are some Onan techs on all of the time.

http://www.smokstak.com/forum/forumdisplay.php?f=6

There is a section just for Onan generators.

Jim

 

One other thing on those ONANS, there is a switch for altitude above sea level, check it to ensure it its not maxed out.

 

Where would that switch be located? Would Rotella 15w40 be ok?

Thanks, good information.

 

Rot 15w40 would be fine. Also the alt adjustment I believe is on the bottom of the carb. Mine was labeled with graduations maked with different alts.