10kw Onan QD light overhaul

[daugen]

I am likely to purchase a used motorhome with a nice looking Onan with 4000 hours on it, oil changed every 200. 57K on a 2005 tag axle, lot of weekend gen running at the races.

I know this gen is capable of at least 10k hours before a major overhaul, but that isn't likely to happen unless I do some serious maintenance to it. I would appreciate any advice on what to do with this gen to make sure it lasts its full life.

On my check list are:
head removed and carbon cleaned out
check for leaks, clean up gen area
new waterpump and belts, keep old for spares
new coolant, maybe a new coolant tank cap
Test and confirm correct voltage
oil, filter, normal maintenance

what am I missing? I want to make this unit as reliable as possible.
thanks very much. drew

[smlranger]

I'd say the following would suffice:

1. all filters, of course
2 new hoses, belt, thermostat, temp sensor
3. while you got it apart, send the radiator to a radiator shop for a good clean and leak check
4. valve lash adjustment
5. maybe new brushes?

These things are pretty sturdy and I believe those that are used regularly last longer than those that get little use. I just bought a coach with the 10KW QD and it only has 730 hours on it.

[daugen]

on my boat I had a relatively ancient 1981 Onan 15Kw, back when Onan was still using their own blocks, and what a clattering smokey beast that was, shook the entire boat. It had both primary and secondary fuel filters on it, plus the supply line had its own small Racor filter.

I don't know what kind of diesel fuel filter this has, but you bet, take it apart, clean it out, put a new filter in. And keep a spare.
Surge tank inspection now on the list, thank you.

[mmccwill]

Remove & check the coolant surge tank for cracks -- The older ones had a problem with them -- Mine is a 07, & it was cracked in several places - Bill Willard

[PapPappy]

Personally, I don't see a need to remove the head, unless you suspect a problem. The other items are good, and I'll assume that you are listing fuel filter with "filter" as part of the normal maintenance.

You may want to look into buying a new fuel pump, and cleaning up the contacts for the 12VDC start system. I had a ground that was sparking (not cool around the gasoline)