socal77 wrote:



Anyone have an idea of what type of costs to expect to service the Onan 4000? I does start right up but runs rough. He did say the oil was low in it.

Mocoondo wrote:



I'm not sure about the price, but I'm not sure it needs a fuel pump at those hours, unless fuel pressure or fuel flow were tested and found to be low.

The Onan Marquis Gold 5500 in my former El Monte has over 3300 hours on it. From the El Monte service record, it appears to have had the fuel pump replaced at 3062 hours:

GEN-ENG-PUMP-O-GENERA,PUMP FUEL 5.5 HGJAB GENERATOR,1,177.96

I'm not sure what the first part means (could be an oil pump), the second is clearly fuel pump, and no idea about HGJAB, either. The number at the end is the price billed to the fleet department by the service department.

It also had that same major service when it was almost new (65 hours), so it sounds like the thing blew up when it was brand new. It also had a lot of diagnostics done at 94 hours. From then until 3062, it had only routine scheduled maintenance (and was well cared for). That major service was probably earlier in the year I bought it (they go by hours/miles, not calendar date), so I expect it to have a long and healthy life. I run it at least once a month, per the manual.

It doesn't mention having had the carb rebuilt, but it starts easily and runs well, so it may have been done at some point.

socal77 wrote:




Thanks Mocoondo, I appreciate the guidance. I just talked to a mobile RV repair guy that's been around 10+ years. He has contracted to do work on CA RV's in the past so knows them very well. He's also Onan Certified. (Also has 21 reviews on his company's Facebook page and they are all 5 stars so he sounds legit).

I told him my Onan 4000 has 1,300 hours on it. He is suggesting a rebuild with new fuel pump, etc. Quoted a price of $950. He said he could just do a tune-up but that the generator would not perform at peak condition.

I'd appreciate feedback. $950 seems high...