We have a 2005 trailblazer 250 two stroke atv that runs great a 200ft where we live in phoenix. If we go 6000 to 7200ft the thing runs like crap and stalls, no power, hard to start, almost unusable!!! Air filter is clean, oil is factory stuff spark plug changed on trip, no help.

Will an air screw adjustment take care of that or do we need to rejet carb when going on high up trips? Help?????

 

you definetly need to rejet, atleast 2 sizes on main jet with air box lid on!! check plug see how it looks! if still rich try taking lid off replacing with duct tape a third of box see how it runs!! if when you check plug still rich try taping only half of air box!! guarantee you will be good to go! when i say tape air box, what i mean is you are making your own 3/4lid, and if not half lid!!! my son has same bike with many, many, mods, this is how we do it!! two jet sizes up then duct tape!! this will allow you to correct for temperature on a daily basis. this is part of having a two stroke!! they can change day to day!! with this method you will not go wrong!! SEMPER FI carlton

 

Have you considered getting a Dial a Jet?

 

What is a dial a jet? How much do they cost in relation to a standard replacement jet?

 

Here you go.
http://www.thunderproducts.com/index.htm

 

The Dial-a-Jet will cost more than changing jets. But it should be easier to jet since you wouldn,t have to take carb off to jet.

 

Hey where do you ride at 6,000 + altitude?

I live in the West Valley and we go to the Cinders and will be going this Labor day weekend.

The wife rides a 2003 250 Trail Blazer.

You totally made me remember to look at that intake. I have never messed with it and need to do something for this weekend in case I need to ride it as a backup (have been doing a project to the Warrior.)

I was thinking of taking the lid off and seeing what holds the filter in there if I can mod that. Have never taken that apart! The bike usually sits.



Now if you have not done a SINGLE MOD to it and need more OOMMPH!???

I will tell you a GREAT mod for that ATV.


The transmission uses that centrifigal clutch and it grabs with the RPM's too low for a 2 stroke when you need the power.

For like $12 you go buy the BLUE spring (I think that's the color it is for the rating) and it takes 30 minutes to replace.

Our 250 will pop a wheely sometimes now! You just have to get used to the RPM's running a little higher.



Let me look for a picture, I am pretty sure I posted it on my website back then...







Here it is ----> tranny Spring mod to my Wife's Polaris Trail Blazer 250

 

Grizz acording to Polaris 6000 to 9000 ft they recomend at 40 to 80 degrees you should run a 110 main jet (turn airscrew out 1/2 - 3/4 from seat raise needle clip 1 position to lower needle) also clutch weight should be 16, blue/green spring ( i think white spring is better) driven spring in 2-2 hopes this helps

 

I'm hoping Grizzflogger replies by tomorrow. I want to know if he's going to the Cinder's near Flagstaff.
That's the only popular place we go at that altitude. And we are going there Friday after a half day at work.

 

we ride in Williams,AZ at 7200' by Crazy Horse lake and Sycamore Canyon. Great ride and awesome scenery.
toslow is correct. We drop 2 main jet sizes and lower the needle or raise the clip. I haven't messed with the weights or springs for weekend trips. We get by, but even the 400 Scrambler suffers at those altitudes.