If your bike is too rich, you would use more fuel. IMO 70-80 miles is pretty typical at a good trail pace with some fire roads.
Actual fuel mileage really depends on how and where you ride. Higher altitude = leaner jetting, more range. Hard terrain and fire roads will get you much better mileage, especially if you are cruising in top gear. If you are in the mud or sand and keeping the powervalve open all the time, you might only get 50 miles. Think about how much more energy you need to use if you push your bike through the mud versus a pushing it on a paved road. Same with your engine! Brenda rides in the southwest - hard terrain, better mileage.
On how you ride, a buddy of mine is extremely fast and he would always get better range than me when we had the same bikes, becuause he rides lower in the rpm range and is often a gear higher. He's going faster and getting better mileage due to his riding style.
Over 100 miles is certainly possible if you are not opening the power valve all the time and riding hard terrain. On my KDX250 I could go over 100 miles on dual sport rides, but trail riding it would do about 70-75. My '90 200 would usually get about the same mileage as the '91 250.
Hhhmmm...too rich=more gas per mile=less miles/tank?
By jove..I think he's got it!!! :eek:
Otherwise, dbd is 'spot on'. On the coast at the dunes jetted for sea level I ran out of gas @ 28 miles on my tank. At Prospect, el. 3500-6500..mostly roads..some trail, rode close to 80 miles and hadn't hit reserve yet.
Mike, I'll bet you weigh more than Brenda, you have a bigger rear sprocket, ride softer terrain, have a race style that keeps the KIPS open more than her 125 mile pace, you are jetted for lower elevation and your '98 has more aggressive porting/KIPS and a smaller tank than her older bike. But the big factor is almost certainly that she is MUCH faster :D
when trying to save gas - keeping it on the pilot jet, i've gone 95 miles and still had a 1/4 gallon left after draining the gas. when at the sand dunes I have killed a full tank in 25 miles! jetting plays a role in mileage, but the rider is the biggest factor. most rides I get about 45-50 miles before hitting reserve, not worrying about miles per gallon, just smiles per gallon. :)