I bought 04.5 Sportsman 500 back in May, already put on about 125 miles. Just changed the oil,
I can only go about 70 miles to a tank. Is this normal range or should it be better?
I feel that the machine is a gas hog.

 

Riding conservatively with a fair amount of camping gear, I got just over 17 MPG on mine. When I ride aggressively, mileage goes down to about 15, which sounds like what you're getting. If you think this is bad, you should ride a 700. We're talking 11 MPG. Need more range? Buy a couple of these for longer trips. They fit nicely on the Sportsman racks:

Fuel Pack

 

I have a 04 sportsman 500 and I run from 115kms to 130 kms on a tank depending on conditions so i'm in the same range as you. We all carry gas for those back woods long runs, check my pic gallery. I got my bike last fall, my first quad, and have 2400kms on it now and I'm loving it.............

 

The Polaris Dealers tell me most are designed to go about 80 miles to a tank. I have a 600 and have ran the main tank and reserve out at about 82 miles riding desert trails. I ran about 10 miles on the reserve tank. I always carried extra fuel and have since mounted a 7 gal tank on the front rack and plumbed it into the main fuel line and installed a shut off valve. They may burn more fuel than some, but what a good ride they give us.

charlie