Thirsty 2002 Polaris 600 Classic

Dear Ralph:
I have a 2002 Polaris 600 Classic that only gets about 10 mpg, on any grade of fuel. I ride with 700 and 800 Polaris machines that will get 14 mpg, consistently, when I only get 10. We all gas up at the same pump at the same time, and it isn’t even close.
Most of our riding is on the trails. I have tried lowering the needles and really didn’t see any change, and I’m at 410 mains. What else I can do?
Bert Akins
Williamson, NY

2006 Classic 600, that’s got an M-10 in it. I’d be curious to know if the 700 and 800 you ride with have M-10 or EDGE suspensions. I’m not totally convinced there is anything “wrong” with your sled, as a Classic with an M-10 is likely going to use more fuel than a EDGE 700 or 800 when compared side by side.
Let’s start with the M-10. Make sure the track tension isn’t too great, and the ride height isn’t too high, this will suck some out of it. Even if these are right on, it will use more fuel than say a 600 with the EDGE suspension. More rolling resistance, taller profile, more frontal area (wind resistance), taller windshield, lower gearing, many reasons. Remember, you’re lugging around electric start and reverse as well, and you make no mention of rider weight differences. But 4 mpg?
You’ve already adjusted the needles to reduce midrange consumption, and your mains are already down from stock and should be pretty good for your elevation, I’d be curious to see what the plugs and pistons look like to see how much room there is here to work with. Basically, is it running rich (by how much) or is it just using that much fuel to make it go? If you’ve tweaked the fuel screws out some to deal with a high idle, this will suck some fuel. I believe the spec for your sled is 1.75 turns out on the fuel screws, may be some here to gain.
Of course, make sure the VES valves are clean (I doubt this will change it, you didn’t mention any other performance issues), and you could check the timing. It might be slightly on the back side of the acceptable range of the specification, a tweak here might help some. Float levels don’t seem to be an issue on this model (are they?) from what we’ve seen. Many shops do install a Holtzman Temp-Flow or ATACC, but again, we don’t know how much there is to gain here on your sled. I suspect the M-10 Classic has more to do with it than a problem that needs to be fixed, but 4 mpg does seem like quite a difference. Do you have a “happy thumb” that likes to pump the throttle? Riding styles of this nature do suck extra fuel as well.