I have a 99 trailblazer 250 which is technically my wife's machine, while i ride a Kawasaki Brute Force 750.

The trailblazer has an issue where when it gets hot, after maybe an hour of riding, it starts to behave as if it is running out of gas. super high idle, but if you give it throttle it wants to stall. I have to pump it constantly to ride it after this happens.
To temporarily remedy this when out on the trails, i have been shutting off the gas from the tank and letting it run itself out of fuel. Once it stalls from lack of fuel, turn gas back on, start it and it's fine for a while.

I have had it in the shop and had them put in new piston/rings (bored slightly), and they could not get it to reproduce the issue in order to diagnose it.

Any help?

 

Gas tank vent hose, when it happens again crack the fuel cap and see if that helps.

 

I wish it was that simple, but I seem to remember (it was 2006 last time we took it for a long ride) the carb being full of gas when this happens.
In any case, I will go check out the vent hose and see if maybe a wasp made a home in there or something.
Thanks.

 

Ok, checked this and it has a solid cap, no vent. The cap has a polaris logo on it so I assume it is the original. There must be a vent hose under the plastic somewhere then, maybe it's clogged?

 

Yep, pull the plastic

 

there is a vent about 4 inches below the gas gap...have to pull the front fender off to get to it. ive been contemplating plugging that hole and drilling a hole into the cap with my own vent.

 

Ok, that wasn't the issue. I took it to a Polaris dealer, they worked on it and put in a crank seal, they say this will fix it since the seal was leaking when the machine gets hot. Makes sense with the way it ran when hot.
I will post in here if this is not the fix.