Why am I getting only 25mpg

[WineGuyD]

I have a 1996 R1100R that I recently purchased with 17,000 miles on it. Took it to the nearest BMW service shop and had them do a combined 16/24k maintenance that included replacing all fluids, all filters, the plugs, the ribbed V-belt. They synced the TB and tuned and adjusted everything and anything possible. Conti Road Attacks are new with about 1k miles on them, wheels are balanced and true. Brakes in great shape with lots of life left on pads. I've been using 91-93 octane gas. And finally the bike has the stock OEM windscreen.

In theory the bike should be running in top form, the specs say I should get an average of 45mpg. When I first got it I went through three tanks of gas and averaged low 30's per gallon, Fuelly.com shows people getting no less than 35mpg and as much as 50mpg. With the bike back and tuned I've done two tanks and averaged 25mpg per tank.

Any ideas as to why such low numbers? I commute on the bike so it gets mixed highway city riding and I'm not a racer, nor do I gun it or rev it high. I plan to take it back to the shop but I'd like to be as informed as possible beforehand so if they try to blow it off I can respond to them.

[ICBMguy]

Not sure. Double check your tire pressures obviously. You may want to try a little fuel injector cleaner. Jasper was running rough after an extended down time and a few local gas and go's that only sold 89 octane or lower. I got fed up and went for the little bottle the gas station sold. Lo and behold he's running like his old stubborn self again. Not sure if it will work for you, but it's probably worth a few bucks to try it.

[peels]

25 mpg? yikes.

make sure both wheels are spinning freely...no brake or bearing problems. Check the plugs for major fouling. Check valves...Then look at the expensive stuff. Motor stuff...loss of compression.

I was sad when my 1150 got 36 mpg....but that was from "right-handus-corruptus" and in town riding.

you dont sit in traffic alot, do you?

Oh, also, you could look for a gas leak. Ive heard of that happening to these things.

[WineGuyD]

Not sure. Double check your tire pressures obviously. You may want to try a little fuel injector cleaner. Jasper was running rough after an extended down time and a few local gas and go's that only sold 89 octane or lower. I got fed up and went for the little bottle the gas station sold. Lo and behold he's running like his old stubborn self again. Not sure if it will work for you, but it's probably worth a few bucks to try it.

Tire pressure good, tires new, trued and balanced. Used only 93 octane, got 35mpg before going in for head to toe service, got 25mpg afterwards.

[WineGuyD]

25 mpg? yikes.

make sure both wheels are spinning freely...no brake or bearing problems. Check the plugs for major fouling. Check valves...Then look at the expensive stuff. Motor stuff...loss of compression.

I was sad when my 1150 got 36 mpg....but that was from "right-handus-corruptus" and in town riding.

you dont sit in traffic alot, do you?

Oh, also, you could look for a gas leak. Ive heard of that happening to these things.

The bike just came back from Bergen BMW where it got a $1000 total service which included replacing every wear and tear part and fluid including new plugs, and synced the TB. Riding consists of 30 miles a day of mostly 60mph highway and a little back roads...no racing. I brought it back to the dealership shop on Monday and insisted they test drive it, in the end the mechanic said he felt some resistance which might be the calipers not releasing completely. They ran some tests and then suddenly the bike would not start so they are working on it now.

[peels]

suddenly the bike would not start

ugh... good luck to you, sir. Yeah 25 mpg is NOT good. Hope its not something TOO bad.