I guess I just have crappy fuel economy

It looks like my 02 VFR just has crappy fuel economy.

Some of you may or may not remember when I first bought my bike it was getting roughly 23 miles per gallon. I put in a new thermostat and that bumped it up to 28 MPG give or take and that's where it remains.

I've replaced the air filter, and tried putting the O2 eliminators on to rule out a faulty o2 sensor. Neither of which had any major impact on my milage.

The bike runs great through out the entire tach and in all gears.

The only thing I can think of left to check is maybe the spark plugs. I'm goign to assume they are original and the bike now has about 23k miles on it.

So plugs left to change as soon as I snag an extra 60 bucks to do that..

What else would be left to look for. I mean I might break 30 if I really baby it in the highest gear possible at any given speed without lugging the engine.

Fuel Filter maybe?

Chip

 

Gearing? Check your sprocket tooth count front and rear. Maybe the Previous Owner changed something.

My 2002 is getting around 32 highway with a Power Commander III, Staintunes and K&N filter. PO changed the gearing however. He went down to a 15T front.

 

If you run into a dead end the next time the valve check is done check cam timing.

 

sounds like -1 front +2 rear on sprockets, I thought I got bad milage at 34-36 mpg on my 6th gen after hearing claims of 50 from some folks.

 

I know the rear sprocket is stock size. I'll have to verify the front, but if it's not stock I can't imagine getting off the line with any higher ratio gears.

 

if you have access to one, hook her up to an EGA machine and see what your numbers look like. If your HC's are high then you may want to adjust your fuel mix. Most VFR's - mine included - are naturally rich running. I couldn't get my HC's down below 800 once the carbs were sync'd. My instructor told me that this was normal on the older V4's and that you could honestly go down to 1 1/4 turns out on these things and they'll still run like a scalded ape, they'll just get better fuel mileage too. I left mine at 2 turns since I was ok with getting 42 mpg. I'd probably only get maybe 6-8 mpg more if I had turned em in further, but when your down below 30 mpg, I think it's something to consider.

If you are running aftermarket exhaust, that could affect your performance slightly too but I think you'd prob already have said that if you did.

I remember you posting about this a while ago, and it's bugged me since. There's just not that many things that could be wrong that would cause a bike to waste that much fuel. Vacuum leaks, float bowl levels, improper plugs, cam timing, valve adjustment... aside from that, the only thing I can think of is performance mods, especially an oversized cylinder. Do you know for certain that the bike hasn't been bored over? I don't know... I'm reaching right now and just throwing it out there.

I'd say it's the fuel mix though, check the numbers and see where you stand.