I recently purchased an 03 AC400 with 110 miles on it and only get about 23 miles before I have to switch to the reserve tank. I have read previous posts that say you should about 53 miles. I drive on some small hills and use 4wd about 25% of the time. The cat seems to run real well, could it be a carb float or jetting problem? I haven't pulled the spark plug but the muffler has some black soot in it. Would a hotter spark plug help?

 

Sounds like your running very rich and with only 110 miles the engine is still breaking in. Check that the carb jetting is matched to your riding elevation and maybe lean the jet one size. My friends 400 didn't start getting good mileage until about 500 miles and at 800 miles is doing fine, but he has rejetted twice. Good luck.

 

I hope theres nothing wrong. I have 37 miles on mine and according to the gauge I have used about 3/4 tank. I did go for a 28 mile ride in n out of four wheel drive, and running farley hard. It seems I am on track with milage.

 

When my friend first got his 02 375 it was very hard on fuel. it didnt start to get good on fuel until he had over 500 miles on it.

 

My 400 gets really good mileage, I get about 100 miles to a tank, maybe a little better than that actually. Guess the big tank gives me lots of range. Not too bad, I can't complain when I drive a truck every day that gets no better than 15MPG.[img]i/expressions/face-icon-small-happy.gif[/img]

 

Not crazy about the mileage with mine (40-50) to reserve and I have 400 miles on it. I would say its using an awful lot of fuel though, perhaps a high float, or some plastic flash from the gas tank has gotten into the carb. You might consider checking the oil level. If its over the full mark and smells like unburnt fuel, get it to the dealer ASAP. Also, check the plug and see if its wet, could be a sticking choke. I plan on rejetting mine to see if I can bump up the mileage. Wish ya luck!

2003 400i auto Lime Green
2500 lb. Warn winch
Hand and throttle warmers
Rack extensions F&R
Front Brush guard
Rear bumper
Third headlight
Dual tool holder
Combination hour meter and tach
Hand guards

 

We have 2 400i manuals and I have hit reserve one time at 98 miles. This is a combination of 4X4 trails and gravel roads. We have a little over 1200 miles on them and have had no problems.