My 4 wheeler has never been over 100 feet above sea level. I live at less than 20'. It is a Honda Foreman it has a carb. (not fuel injected) If I take it to Arizona/ New Mexico up to 10,000 feet will it run or do I need a jet change?
Thanks
Frank

 

If the carb is a constant velocity style a jet change is not required.

MikeyB

 

itll run better if you would. you can probley get by with out it, but i would diffently take an extra spark plug with ya. Dad took a 350 honda out to colorado and he kept the plugs fouled outta that thing.

 

It will still run at those altitudes but will be low on power. If you do rejet it make sure to error on the rich side as it wont hurt anything but lean is VERY hard posibly life thretning to it. I live at around 1500 feet and make trips to colorado every year. We camp at around 9500 feet and ride up to 14000 feet. I rejet the machines at 90-95% of stock. In other words if your main Jet is a 100 then put a 90-95 jet in. The bigger the number the richer it will run. That is a little rich but I would rather be rich than lean. If you know how low you will be riding at i would jet fot that and just accept the rich conition at higher elevations. I am not certain on this but if memory serves me most stock machines are jetted for 0-4000 or 6000 feet. I would posibly go down a little maybey run it at 95% of stock jet size. This is all asuming the machine has stock intake and exaughst. If you have aftermarket exaughst or intake these numbers may be wrong.

 

Ok what is a constant velocity carb and how do I know if i have one? It is a 2002 0r 03. I forget.

 

I dont think it has one. The only ATVs I know of for sure that used them where older Polaris machines.

 

1 i bet it aint and 2 look in your book, im bet that it says what to do in higher eleveations. all we own is hondas. weve got about 4 or 5 of em and they are THE best fourwheeler made.

 

A CV carb uses vacuum diaphram to control the slide bore. Easy way to spot a CV carb is the throttle cable linkage is mounted on the side of the carb, not on top like the throttle controlled slide bore carbs.
I have ridden street bikes in the mountains with the old slide bore carbs and the newer CV style, and let me say, the CV carbs are not as finicky when it comes to altitude changes.

MikeyB

 

i have 2 450s. they were purchased in nevada where they are set for california. we recently moved back to nevada after 2 years in colorado. they run great in nv(4200') and they ran great in colo.(10000')

 

Thanks everybody. I should mostly be lower than 7000' but I am not sure.

 

If the jetting and intake/exhaust is stock you'll be fine. They are so lean for emissions it is not funney. I have an XR400 and it ran like a champ between payson and Flagstaff (6500' to 7000').

Randy

 

If your going to be below 7000' I would say to just leave it stock. You will notice the power loss but it wont be a real major issue.

 

Maybe this will help out. We have 2 Honda Rincon 650s that we take out to Colorado every summer. Last year we rode in the San Juan mountains above 13500Ft. I bought a couple of 142 Jets but never installed them. I also bought a couple of extra spark plugs just in case they fouled out since the ATV will be running much richer at that altitude. We never rode at an elevation below 9000Ft and we never had any problem with them. The only thing that I noticed was that it took a little longer for them to start in the morning and they had a little less power at that elevation. Our ATV's will run 63 MPH at home and I could still get them up to 50 MPH at 9000Ft.

So long story short.... We never change them from stock and they run fine. You shouldn't have any problems. If you were going to stay out there for a long period of time I would probably change the jets but if not I wouldn't worry about it.

Here is a picture that was taken at 13300Ft.



Britt

 

only 63mph? a buddy of mine had a grizzly automatic and i got that dude up to 72. im never gunna buy a yamaha, but i jsut thought the rincons would be faster than that

 

Nope. A buddy of mine has a Grizzly and it will beat mine at top speed every time. I weigh 185Lbs and he weighs over 250Lbs. Grizzly's are nice no doubt about it. But I just like the ride of the Rincons myself. They really could use a "real" low gear though. Low gear doesn't kick in until 5 MPH and sometimes on a rocky slope 5 MPH is pretty fast.

And besides, 63 MPH is way too fast on an ATV anyway.

Britt