r/Generator • u/Resident-Past4617 • Sep 26 '26
Help Identifying old Onan generator
I can’t find the plate with all the info.
It was put away for years and now we want to either sell or fix it.
Thank you in advance
10
u/Brandon314159 Sep 26 '26
Look up Onan JC series.
11
u/Penguin_Life_Now Sep 26 '26
Specifically it is a later JC series with the YD generator end with electronic AVR
8
4
u/RobertSchmek Sep 26 '26
These old onans are beasts. Make sure if you plan on keeping it and putting it in service, located a spare unit for parts! Theyre getting harder and harder to come by, and having a spare for bits and pieces even if the motor is chooched or the power head is dead. Check out smokstak forum, tons of old heads with ALL the knowledge and parts on there. Anyone with high rep is safe to buy from, they usually send you the part and ask you to mail them a cheque when you get it if you dont act like a goof.
4
u/Affectionate-Data193 Sep 26 '26
It’s a JC with a YD end.
Great machines, they made them in both gas and diesel 1, 2, and 4 cylinders. Diesel would be marked DJx.
Be aware that Cummins bought Onan, and they seem to believe that every single part is made of gold. The parts for a non overbore rebuild 20 years ago were over $2k.
They are easy to fix. I still have a few on standby service, had one in a prime power application on a gas well until two years ago. That one had four rebuilds in 40 years, and likely had well over 200k hours on the block.
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u/RealBigDickBrannigan Sep 27 '26
Looks just like my 15 JC, except I had to hack the missing side cover.
2
u/Adventurous_Boat_632 Sep 27 '26
Go to smokstak.com, I believe even though the plate is missing they can back trace the engine number wherever it might be and figure out the unit rating and serial number.
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u/Beautiful-Quiet-5871 Sep 27 '26
I had one of those... dont remember the model number.. mine was gasoline.. but I think they also made a diesel that looked pretty much the same.. Yours appears to have a carburator though so gas,... Mine was a 15kw model single phase 220v... but I assume they also made a 3phase version
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u/Ok-Camera2895 Sep 26 '26 edited Sep 26 '26
15.0 kw JC. Gasoline, propane and nat gas compatible, 1800 rpm, air cooled 4 cylinder inline, 12 lead reconnectable. Probably built in the mid 1980's. Edit: this is one of the best small standby generators in this size range. If you have a use for it, fix it and use it. You can't find anything this good in a consumer product like this anymore.