High altitude Genny carb mods

[Smokyroo]

Hi folks,
After reading my instructions again , Yamaha is suggesting I MAY need the high altitude kit when using the generator above 4,000 feet. My summer trip out west this year is largely above 4,000 feet. The instructions also say using the high altitude kit below 4,000 feet will damage the generator.

So, how critical is having this kit for campgrounds say at 6,000 feet? About how much power is lost not having said high altitude kit? The genny is 3,000 watts. I have a 13.5 k btu air conditioner I may run say at Zion NP. What say you guys?

[NMWildcat]

I wouldn't worry about it unless you have problems. I live at 3900' and use my Hondas regularly from 6000' to 8900'. Never changed the jets, never noticed enough power drop to worry about. Of course we rarely run the a/c at 8900', but run the a/c almost constantly this time of year at 6000' (Lake Roberts NM). Have also used them at sea level.

I read about folks who change their jets regularly when changing altitudes, but I've never had a reason to with mine.

[Smokyroo]

Thanks NMWildcat. I won't get out your way often so the desire to change the jets for me is minimal. On our trip the only area I foresee the need to run the a/c is in Utah. The rest of the trip we will either be in Yellowstone or state parks. The state parks all have 30 AMP service. Good to know it will likely run fine.

[dbledan]

In Utah now (Eden in the valley) and using Yamaha 2k without any issues or a rejet. I am not sure how high Zion is compared to where we are but we are also only running one without AC because it has been so cool. I forgot about altitude when we left.

When running ac I bring my champion duel fuel. They provided a rejet kit for free but I just use propane so I don't have to deal with changing the jet. I have not really had any issues but you could always ask Yamaha for the new jet and have it with you just in case.

[jimmoore13]

"Your mileage may vary" as they say, but my Generac lives at 8300 feet and camps higher. No changes from box stock, and it was sold in Denver--5280.
I've been running it on the factory plug since 2014. Just change the oil and add fuel.

Since your planned altitudes are borderline, I'm thinking you have other things to worry about. :-)

[jkoenig24]

I had a Honda Handi 3KW unit years ago. After about 7~10 days in Mammoth CG (elevation ~ 6200 MSL) Yellowstone, it would not start. Turned out that the spark plug had fouled. Once the fouling was cleaned off, it when back to its' easy start, rock-solid reliability again. Shortly after the cleaning, I returned to a lower altitude and never had a problem.

Honda has a "High Altitude Kit" BUT, recommends that it be installed by an authorized dealer. It would then have to be changed back once I returned to sea level. Too costly and troublesome as far as I was concerned. In years past, some carbs had user adjustable carbs. I was told by a small engine repair shop that the laws had been changed preventing manufacturers from offering that owner adjustable feature. If that's correct (and I believe it is), it's just another example of the government knowing what's best when the truth is that they often don't have a clue.

[Smokyroo]

I take it the original jets are going to run the motor rich. The high altitude jets run it leaner but at sea level the genny would too lean and thus hot.

I will run with the factory installed jets. Just for kicks and giggles, what other issues do I need to concern myself with at elevation ;-) lol..?

[NMWildcat]

Originally Posted by Smokyroo

Just for kicks and giggles, what other issues do I need to concern myself with at elevation ;-) lol..?

Well, trapped gas does expand at higher elevations, so I always use that excuse for farting. Liz doesn't seem to buy it though...