Generator Carburator Alititude Adjustment

[mk-ultra]

Just thought I'd pass on one bit of useful info we discovered this year.

After the second big dust storm, the gennie in one of RVs was running really rough, and would croak when it was put under load.

I popped the lid off of it to remove and blow out the air filter. It was pretty caked, but I don't think that was the real issue. It sounded a lot more like the plugs were fouled.

While noodling around I found a mixture adjustment on the carburetor -- variable from sea-level to 10,000 feet.

I tweaked it for 4,000 feet (near playa altitude) and let the gen run for a while, and the plugs cleaned-up nicely. All was fine after that.

This was a Cummins Onan generator. I understand that the higher-end Honda EU's have an automagic mixture adjustment that doesn't need tweaking.

Here's a pic of the altitude adjustment (see yellow label):



Next year I know to tweak this as soon as we get out there

[ygmir]

that is a great option.
you go leaner as you rise in altitude. If timing is adjustable, you also advance as you rise.........

[geekster]

Another rule of thumb is that you lose about 10% cooling efficiency with every thousand feed of altitude, too. Another data point to keep in mind when designing generator enclosures.

[The CO]

The Honda EU gennys are not foolproof in that regard; the manual recommends taking them in for adjustment if you will be using them above 4500 feet for extended periods. Mine, however, has done great the last two years with no adjustment, as have others used by our camp.

[motskyroonmatick]

That is a really cool option!!