I have a 50' houseboat which came with a little 7kw Onan RV generator (a
Marquis 7000). It has worked really well (since 1999), running the two
rooftop A/C's and pretty much anything else we needed. Has about 500 hours
on it. Changed the oil regularly - and it's never run low on oil - but the
day after the last oil change it started "ticking". Sounds like something
in the valve train. Cut open the oil filter & did find a few small
"shavings" of metal. (DANGIT!!). So I'm planning for a replacement. A new
"same unit" is about $4,000. A new "Marine" unit of similar size
(Westerbeke, Kohler, etc) looks like it would be around $6,000 to $7,000 (or
more).

I really want to stay with a gasoline unit as I have only one small (40
gallon) tank that runs the Honda O/B motor & the generator. It's enough for
a full weekend but that's about it. Here are my questions/concerns:

1) What's the diff between an RV unit & a MARINE unit?

2) What about brands? Onan vs Westerbeke vs Kohler vs Guardian/Generac vs
anything else? I found a Guardian 7.2k RV unit for around $3,500 but I know
nothing about them.

3) Is water cooled better than air cooled?

4) What about the RPM issue? I think the Onan was 3600 rpm's, and the
Guardian is something like 2500. Seems logical that a unit that can do it's
thing at lower rpm's might be quieter - is that true?

5) What else do I need to know or consider?

Thansk in advance....

Bugman