High Fuel Consumption

I bought a '99 Honda CBR600 F4 under 7200 miles back in 8th of this month. And there's a little maintenance issues that needs to be done. For example, replacing the front tire and changing the oil. Also when the speed drops below 20 mph, the front brake fades in and out, it grabs and then it lets go every 1/2 second.


Anyway, my question is I'm not sure why, but the bike is really burning a lot of gas. Most of my riding is in town with few traffic stops, so far haven't done any freeway riding with the CBR. Mostly I stay in 3rd or 4th gear, and sometimes 5th for few minutes on long stretch of road. Mostly I let the bike cruise at 5-6K rpm and occasionally let it fall at 4K rpm during braking. When accelerating, I don't usually take it above 8K rpm, mostly run it at 7K rpm before shifting up.

So with all that said, I'm getting 80-90 miles out of 3.7 gallons of gas before it hits the reserve, that's about 21-24 mpg.

The bike itself seems to run fine, carburetes well, no hesitation on starting it up. Once I notice white smoke coming out of it when it was cold and gave it some throttle. But that's about it, I never need to use the choke to start it up. There's no hesitation in any of the gears or rpm, and it pulls quite smoothly.

The rear tire is practically new, and like I said, the front tire needs to be replaced, it's pretty bald.

The bike seems stock, no aftermarket stuff, even the OEM license fenders is still there.

So I'm just scratching my head about what could it be?
Here are few pics:

http://files.automotiveforums.com/gallery/watermark.php?file=/503/193855bike01.jpg
http://files.automotiveforums.com/gallery/watermark.php?file=/503/193855bike02.jpg
http://files.automotiveforums.com/gallery/watermark.php?file=/503/193855bike03.jpg
http://files.automotiveforums.com/gallery/watermark.php?file=/503/193855bike04.jpg

i get about 110 outa my 98 but i ususaly run about 3.5k shift about 5k btw my brakes do that too maybe just a cbr issue

I have a 93 CBR 600, and I usually get 50mpg. My riding style consist of about 4.5k I shift to next gear, and usually cruise around 3-4k (5k out of town always in 6th). I usually won't take it over 6k unless I need to get out in a hurry. Reguardless though, its always been about 50mpg. When I first got it, it burnt gas at a faster rate, but about 50miles later, was good. Your bike should definately be getting a lot better milage, and I don't really think your riding style is causing the bad milage. Is it running rich? Have you checked out your air filter? Maybe you should replace your spark plugs? I had NGK-Rs in there when I got it (milage wasn't as good). I replaced them with some cheap autolites that were like 1.25per at the local advanced auto parts store. My milage was a lot better after that, and I feel no difference in performance.

My brother has an F3 that was burning through gas in a BAD way... kinda like you described... Make sure there isn't a gas leak from under the tank. His leak was dripping right over the air filter... he's damn lucky it didn't ignite at any point. I forget what they replaced on it... I think one of the gaskets, but I could be wrong.