ONAN 5500 @ high elevations

Team Roper Heeler wrote:
My wife and I will be heading west in September. Overnighting around 9000'. What do I need to address to insure optimum performance. We currently live around 1,500'. Thanks for the help.

Gasoline powered generators do have a carburetor altitude adjustment,,,if you have a gasser....

Effects Of High Altitude And Extreme
Temperatures
If you travel at high altitudes or in extreme temperatures, your generator can lose power. In such lower-density air conditions, you can’t operate as many electrical devices as you could under normal operating conditions.
Power decreases 3.5% for each 1,000 feet above an altitude of 500 feet. For example, to operate at 4,500 feet (4,000 feet above rated generator altitude) multiply 3.5% x 4 (4,000 ft) = 14% power loss. Then multiply .14 x your generator’s power rating: 4,000 watts x .14 = a loss of 560 watts at that altitude.
Power decreases in extreme temperatures by 1% for each 10° F (5.5° C) above 85° F (29.4°C).
NOTE: The carburetor on a non-EFI gasoline generator may require adjustment at high altitudes. (See your Operator’s Manual or your Cummins Onan Authorized RV Service and Parts Dealer.)

At 9000 feet you more than likely won’t need A/C. An adequate solar system will provide you with good battery recharge capability...no need for the generator almost every day.

I going to ask the question others are thinking
Are you going skiing, are you a glutton for punishment
Or maybe just a "dark sky" astronomer

Why in the world overnight at that altitude and cold temperature
Better keep the furnace on and the cabinet doors open
Or be winterized

I went thru Flagstaff Az in Nov one year (I think it was 1996) In my First class A
AND THAT WAS COLDER than I wanted to be, and that is not as high as you want to do
Sept in the Rockies ? At 9000ft is freaking COLD
I FROZE my wavos at night at 7000ft in the Searres in July in a tent at 30°

What Ed said X2. I wouldn’t worry, not like you’re running the AC units. I don’t have issues running my 3k gen for microwave, etc. at that altitude.
Mr Wizard is right, it can get cold that time of year but run your furnace and you’ll be fine.

Mr Wizard-some of us are gluttons for punishment and spend the winter at 9k ft just to ski :).

Turn the carb adjustment to 10,000 and enjoy,

roam1 wrote:
Turn the carb adjustment to 10,000 and enjoy,

Yep! That's what it's for. Just don't forget to turn it back down to the proper altitude when appropriate. There is a danger of overheating/damaging the engine if you forget and don't.

Chum lee

To clarify, the adjustment they are referring to is inside the cover of your 5500 and is clearly visible.

Thank y,all for the information. We are just overnighting in the Rockies on the way west bound to Yosemite. I was just curious about having to adjust the carb. Thanks again for the help