I have property at the 7,750' elevation of the Rocky Mountains and would be riding up to 12,000' My two questions are:

If I rejected the BF750 for 8,000' how will the it do at those altitudes?

How much of a hassle is it to rejet the BF750 for when I go down to 5,000' or sea level?

 

Rejetting isnt hard, its just time consuming.
My opinion, get a Polaris brand ATV with EFI if you go riding at altitudes a lot to avoid rejetting.

Regards,

 

In my opinion. I would not take 2 Polaris atv's for my Brute. I have never rode at 12,000', but ride at 10,000' all the time. My brute 650i has the jets that come shipped from the factory in it. It would probably help the way it would run if I would rejet it. I can honestly tell you I never have a issue with the way it runs no matter where I ride. To me the efi I thing is not all it's cracked up to be. But then again, I ride a brute where efi is not an issue only because they run so good.

 

I ride anywhere from 3000 to 11000 ft with stock jets, seems to run just fine.

 

This is good to hear. My driveway is at 7,750' but in the hills in back it goes up to 13,000'. The Continental Divide Trail is also near.
Thanks for the reply!
Jim

 

Like I replied to alltoos,
This is good to hear. My driveway is at 7,750' but in the hills in back it goes up to 13,000'. The Continental Divide Trail is also near. I imagine it would run a lot better if I rejetted for a leaner mixture.
Thanks for the reply!
Jim

 

With stock jets that were lean at 300-500 ft I made it to 12,152 ft (my gps) on MT Elbert in CO. running 85 octane bought in the town of Leadville.I say that because we dont have any thing lower then 87 here in east Tx.Thats all it had though I could not go any farther, it wouldnt even idle and was a pain to get restarted.Rode all over the national park thats South of there though,and it ranged from 7000-9000 ft.

 

klt1969,
Having worked on reciprocating engines for over 50 years I'm amazed at the altitudes you guys have ridden at! The optimum altitude for a normally aspirated gas engine is approx 7,500' and you normally have to lean an engine when they go above 3,000' to 5,000' to maintain sea level power. I have a digital exhaust gas analyzer and I was thinking I'd rejet for a minimum of 5,000' or for 7,750' which is the lowest altitude of my property in the Rocky Mountains.

I'd like to hear from others as to the altitudes they've ridden at and how it ran.

Kawiking33,
I have brothers who own Polaris ATV’s with EFI and I want a SB750i but thanks for your reply.

Thanks again everyone for your replies,
Jim

 

I live at 6400ft & ride here in our Mountains at about a avg of 8500ft.
I did have my Brute 750 rejetted one step to 145F/152R, runs, starts great anywhere from 2500 in the lower NM deserts to 14,000 ft up in the Colorado Rockies.
I'd say do the re-jet.

 

bfb750BF,
My place is up close to but a couple of ridge lines below the Brazos Cliffs in the Ponderosa Subdivision close to Chama. Brazos Peak is behind my property at a little more than 11,000' and the area is full of trails right from my property. You have the same 07 BF750 but a different color than I ordered and will be receiving soon. I'm having it flown into ABQ and I'll pick it up later this month when I go back to NM from N CA. I'm glad to see how you rejetted your carbs. It will be a good starting point. Thanks for the info,
Jim