I just got a 2003 Prairie 360. It is Jetted for 12000 feet. It barely runs in Denver at about 5000 feet and I plan on running it at about 9000 feet.

Do you think I need to rejet?

If so how much of a job is that? The carb looks tight in there. Would I need to take it off? Once it is off how hard is it to change?

Thanks for the help and I look forward to entering the worl of ATVing

 

<div class="FTQUOTE"><begin quote>Originally posted by: mikem74

I just got a 2003 Prairie 360. It is Jetted for 12000 feet. It barely runs in Denver at about 5000 feet and I plan on running it at about 9000 feet.



Do you think I need to rejet?



If so how much of a job is that? The carb looks tight in there. Would I need to take it off? Once it is off how hard is it to change?



Thanks for the help and I look forward to entering the worl of ATVing</end quote></div>

Have you tried to choke it at 5000 feet. If jetted for 12000 then you are jetted lean. You possibly could be ok at 9000 if not try choking it a little, because you don't need so much air, you would need more gas so cutting the air back could have it close to a correct mix.
To change jets, yes you need to take the carb off, unless you can fit a screwdriver under the carb while it is on the machine. Take the float bowl off and unscrew the main jet and screw in a different one.
Do you know what size is in there now, and also what size was the origional jet?
If you knew that, then rejetting could get you closer to the correct one for 9000 feet.
If it came with a 150 and now has a 140 you could try a 145 or 147 for 9000 feet.
Jets are pretty cheap you can get them for about $2.00 each.

 

If you are going to be going up and down in elevation quite a lot in a years riding you might want to look into a Dial A Jet system. Allows quick and easy changes in jetting for elevation changes. Adding a bit of choke is a way to see if you are really running lean but no a good method for continuous operation.

Do a search for topics on jetting or Dial A Jet to get the information you need, I know folks that have installed them and they are quite happy with the results. I have not installed any as my riding is normally from sea level to around 3500 feet.

Good luck with your project and ride safe.

 

As tencubed said 'Dial-a-jet' is the way to go for being able to quickly change jetting.
The link is here:
http://www.thunderproducts.com/dial_a_jet.htm

Dial a Jet is a wonderfull product and is on my Christmas list for sure.
Choking will quickly tell you if you are way too lean and in a danger zone, and as a temp fix, can at least save your engine untill you can change jets before a melt down.

 

I just ordered the dial a jet. I hope this will do the trick.

So from what I understand it is easy to install. I currently have the high altitude jet installed so I just need to install the dial a jet. Anybody have experience installing one on a 360 Prairie. Will I need to remove the carb?

 

From what I have read you will have to have the carb off the engine. Hopefully someone on here will post that has hands on experience with this as I too would like to know how difficult the process is.

I have also read the factory gives very good assistance by phone when help is needed.

 

Not to burst anyone's buble here but what I have read regarding the dial a jet, is there not worth the money, there was a guy on the forum by the name of Olemanmooses, he was considered the #1 mastermind on the 360, he hated it, however I will say he lives in PA, & really has no need for one out there.. That said I have ridden the 360 for 5 years, put over 7000 miles on mine & ride very simual terrain & elevation I'd guess you will be riding, anywhere from 4000 - 12000ft.. Kawi's manual reccomends a 145 jet for those conditions, I installed it & it ran WAY to lean, I was actually backfiring allot. I tried every yet from a 145 to a 155 (stock) & found the 148 to be the best all around jet for those conditions.

I cant personally speak for the dial a jet, but I cant honestly remember to much good being said about it, I could be wrong but thats what I have seen.. I will also say when I 1st purchased my 360 I rode it up to 10,000 ft, damn thing had lost a bunch of power, after I rejeted to a 148 it made a world of differnce riding that high.

 

I will agree with Uinthas on this one. I also read a lot of dislikes from people trying the dial a jet. on the 360's It made me a believer not to try one. The only personal experience I can say from them was on Hondas Foreman 450. It made it run so badly that it had to taken out. It may have only been a foreman 450 thing I don't know.

Good luck only my opinion,
Mud