How high can I take my Polaris Sportsman 500 2003 model without rejetting.?

Question

I know you are supposed to rejet the carb at high altitudes, but I'm wondering if I can get away with not doing it at around 9000 ft. I don't want to spend the money if I don't have too. Besides I'll just be there for a week and will have to change it back when I get home.

Answer 1

I was in Colorado last fall hunting Elk and rejetted my 500 H.O. to a 148.5 and I was still WAY too rich. That was all between 9000 and 10,000 feet altitude. It nearly fouled a plug out in just a couple days worth of sporadic use and every time it idled at all, it just about flooded out the spark. It really was way too rich for a that kind of altitude. I'd go one jet smaller yet if I was to redo it, but the factory jetting would really be awful.

The other alternative, and I think this is a bad idea, is to just run with your breather box open and change the air filter when you get back. You will let way more air in which will lean you back down, but the problem is you pick up a lot of dirt and dust that way. It works if its not too dirty, but I surely wouldn't recommend it!