Heading out to Paiute Trail in July. Elevations between 6000-12000 feet. What modifications do I need to make on the Bruteforce 750i before I go. Also, my wife has an 05 Kodiak 450 that I will need to modify, any suggestions? Thanks.

 

You are planning quite early... it's only March now.
You may need to lower the the main jet size one size smaller. The front BF750 carb has #152 and the rear has #158 as a factory setting. With stock setting, you would feel less power in WOT situation. If you want to be perfect, install new plugs and run at WOT for a while at the high elevation. Then do your plug reading and determine what size you would need to bring it down.

 

I rode it last year in July and did not rejet. The BF750i is lean from the factory so it's not as bad as you might think. You will notice a drop in performance, but even if you rejet you will still have a significant drop in performance just not as large due to the thinner air at 12000 feet. I will be riding it again over the July 4th holiday. Last year we could not get al the way through due to the heavy snow fall last winter. This year looks better.

 

Thanks for the help. We are going to be there July 10-15 in Marysvale. Should I even bother with rejetting then? Some of the sources from the area say yes.

 

If you will be joy riding at around 20~30 mph on trail - no need to.
If you will be racing against your buddy up the hills 40+ mph - yes, you should.
BF750 is just a pure PITA to get to the carb...

 

I'll second what hayashi said. Installed a hmf slip on and dyno jet kit on my buddies bf750 today. The pipe was childs play but the carbs are buried under a mountain of plastic and other crap. The jetting was no problem just getting to everything was a pain compared to my 700p. Followed dyno jets instruction on the recomended jetting and it seemed to de dead on, what do ya know something that finally worked right the first time[img]i/expressions/face-icon-small-smile.gif[/img]

 

Fastfatboy,

I am getting ready to install the dynojet kit myself.

1) What jets did you use?
2) What elevation did you jet for?
3) How long did it take?
4) Did you adjust the air/fuel screw, if so how many turns?

Thanks [img]i/expressions/face-icon-small-smile.gif[/img]

 

Jut finished with the jet kit. Took 4 hours what a pain in the rear. I could do it in about two hours now, but jeez that sucks. My dirt bikes take 2 minutes if I am sleeping. I really hope I don't need to jet again when I go North this summer. Maybe I'll buy a pipe and just install that as I go up in elevation. Anything has got to better than tearing all that freaking plastic off again.

 

Yes your jetting will take several hours there is no way around taking off the plastic and removing all the carbs. The folks at dyno jet know what they are talking about. Jet what they say to and it will work. And it WILL make a difference I have never rejetted my big bore bikes for going out to the piaute I go every year to the Fillmore Jamboree and all I need to do is turn up the idle at the higher elevations and it runs fine. No matter what you do you will not have the same power as home but still plenty to wheelie. I put in the third and second to highest jets in the kit and it according the dyno runs perfect on A/F ratio.

 

For anyone interested in the rejetting issue, I called South Valley Motorsports in Utah and they said they set up and use a 125 in the main for the 05 Kodiak 450 and 142 and 148 in the 06 Bruteforce 750. They recommended this as an average for elevations between 4500 and 7500 and it is the best range for the area. Just fyi.