The same people that make the dial-a-jet also have a filtered valve called a low boy that fits on top of air box cover.
Since I ride between 3000-9000 I'm looking for a solution without installing dial-a-jet or re-jetting.
I added a dg snorkle and twinair filter and it was still not enough air for 8000 feet with stock jets.
Anyway I have a couple TPI low boys coming I'll try.

 

Hello Minimus

i tried one with the 360, to try and lean out the main jet, and I dont know if it caused turbulence or what, but I cannot get the bike to run good at all with that stinkin little slide on the lid open. i also dont think I like the idea for that rare instance when you unexpectedly get into deep water, Good luck with yours and let us know any results. Mine is presently siliconed shut

 

Send them back~LOL. I bought the ITP value for my quad and it seems to let the air in ok,, but is not water proof and dust -n- dirt can get past. There filters I think was made more for street bikes? If I had to do it over again and I was looking for a lot of air flow. I would get an outerwear for the top of the lid. I cant think of the company? EMX? something like that? There in the ATV mags, they make a bolt on set up for the lid and I know outerwear also sells there filter skins if you want to remove the lid all together and cover it with the outerwear. That maybe your best bet? Also The Prairie is VERY easy to rejet and would be something to think about doing anyway just to get it running at peak proformance. ~coop

ww.MarylandATV.com
Prairie 700
Team Green Plastic
Progressive Springs
OMF Beadlocks
Maxxis Big Horns
Dyna CDI
EPI Pink Spring
Twin Air Filter
HMF Penland Pipe
And a Bunch of other Toyz

 

Thanks for the feedback.
I was hoping this may be the solution for high elev. changes.
I've never rejetted before but would have to rejet several times a month.
Was looking for a simple solution. More air, less air with a simple slide on the air box.
I'll give some feedback if it works or does not for my riding situation. I have 2 coming
because of the high altitudes I ride at.
I don't think I have to worry about the air box getting under water in this area.
I'll use a rubber and gasket adhesive around the base so I'm not worried about
dust getting under the lowboy. If the filter is crap then the twinair will back up I hope.
Thanks again and expect a report later.

 

Hi OleManMoses,
Just looking at your mods, don't believe the TPI Air Box was right for you.
I'm no expert but guess in Pennsylvania 0-2000 feet the extra air would make you to lean.
You would gain no horses unless you jetted up big time.
I know from experience if you start screwing with a larger exhaust you can loose power on the low end.
You have to make up for it with more fuel and air. Apparently the Dial A Jet did not work.
Did you jet down 3 jets ? Prior, Per dial a jet instrutions? That is the only way it will work.
I'm looking for a simple way to not have to deal with re-jetting in the mountains.
I'm not telling you that you screwed up because I don't have all the facts.
Just saying it may not work in you elevation veres mine.


mods by OleManMoses
Nyroc Muffler Mod(sort of)
Dial A Jet (doesn’t work for me)
TPI Air Box Valve (Hurts performance--do not install)

Thanks for the input . I'll keep in mind what you said.

 

Hey Minimus

I never did jet lean enough to get the diala a jet to work---my stock jet was a 155, and I purchased every jet from a 150, to a 180. the richer i kept going on the main, the more top end i kept losing---with the 150 main, the dial a jet still was not working, but my top end power and speed is the best i ever felt it---I did not try jetting leaner than the 150 main though. I figured with all my mods including the advance key that i would need richer main, but not the case. I did bump up the pilot jet one size which took away the backfiring on decelleration. As for the TPI---I tried all kinds of scenarios with the air box, running with the lid off, snorkel removed, replaced snorkel with radiator hose, nothing works better than the stock snorkle. I also tried the mods with all different size jets, and bike always ran worse. My best results are with my present setup---I will say again, I think my 360 is about perfect with the mentioned mods. But i still havent been able to find a stocker to compare it too.

 

Thanks for all the info, I have some serious concerns but would like to give them a try.
I'll know a lot more after doing some test at 8000 feet.
As you can see sea level test and 8000 feet are going to look different.
I sputter and backfire along with a friend of mine at 8000'.
He sputters even at 6000' when I seem to run ok with the DG snorkle.
We did a race at 8000 feet 2- 700 prairies. 1 stock and the other with a dg3 , dg snorkle.
He killed me off the line every time because even in 4 wheel drive I could not keep from popping a wheelie with fuel and box on the back.
Then I would catch and pass him at 64 mph with a large utility box and 3 gallons of spare gas.
My friend said the best his stock Prairie would do was 59 mph at 8000 feet and he weighs 166 and I'm 225, when we raced.
Both machines backfired when letting off the throttle. And sputtered at about 1/2 throttle when doing casual riding.
We also had a 2004 Grizz that was an impressive ride over rocks. He claimed to get up to 62 on the speedo but never would race.
A Honda Rubicon would only do 52 up at that elevation. Normally will do 56 at 4000 feet. Both the Grizz and Rubi backfired like the Prairies when letting off the throttle. Just not as often.

I should clear up a misstatement by me. My friend that has the Grizz never turned down a race, we just did not have a opportunity to race.
He verbally conceded he did not think he was as fast so I never pushed him to race. Wow now I feel better.

 

Hi OleManMoses,
Reading your post you did a hell of a job.
You may have jetted down to 148 even 145 for better dial a jet performance.
150 looks to Rich even at sea level with the 360.
Interesting though.
I'm still looking at the dial a jet as a fix it for my elevation changes.
Thanks again for the input, and don't listen to me what ever I do when it comes to jetting.