I have a 01 f4i with 55k on the clock (says the ODO) not sure if thats true or not. Right now I am getting about 80-85 miles till my reserve light kicks on. I'm not riding aggressive and 90% of the time I'm riding is on the highway at 75mph.

Maintenace:
Spark Plugs (NGK)
Cleaned Air filter (K&N which smelled like gas)
FPR
Oil Change
Coolant Flush

Mod wise the bike has a 520 chain conversion, K&N filter, and a scorpion slip on. I have no idea if a valve adjustment was every performed. I signed up for a Valve Adjustment clinic at the MotoShop in SF so that will be taken care of soon. I can hear my CCT rattling, but that will be replaced with the manual cct I received in the mail. Could the valve adjustment and the cct play a role in my horrible gas mileage?

 

my bike has 43k miles on it with valves never having been adjusted and i still get about 35mpg if i didnt ride aggressive so not likely the problem?

 

When your fuel light comes on, is it really that low?
Does the exhaust smell like its running rich and black or grey smoke coming out the pipe?
Oxygen sensor installed or bypassed? (you said SF, m assuming its a cali bike)

Other things that can cause rich running:
Coolant temp sensor bad
Oxygen sensor bad
Vacuum leak, making the bike dump fuel to compensate
Leaking injector, would be running bad
FPR or plugged/kinked return line.

Did you remove the plug that came on the fpr before installing it?

 

Reserve light doens't mean anything, actual gas mileage does. Fill up to a specific spot, go ride, then re-fill at the same pump to the same spot and calculate your mileage.

You said 520 conversion, you sure it isen't changed gearing as well? How many teeth do the sprockets have or whats your rpm in 6th gear at 50mph? Stock will be right at 4000rpm.

 

Yes the fuel is low in the take when the reserve bars kick in. The oxygen sensor is installed on the midpipe.

Yes the exhaust smells rich but not as bad as it was before I installed the new fpr.

I did remove the little plug on the fpr before installing.



I was told by a "mechanic" that it has a 520 conversion I honestly cannot say fore sure. I will check and find out what RPM's it at 6th at 50mph and post back up.

 

There should be a number on the rear sprocket that tells you how many teeth it has. You can always count them.

 

I rode the bike in 6th at 50mph and it was at 4k rpms. Also the rear sprocket says 46. So I have stock sprockets.... I'm assuming the front sprocket is stock also. I will remove the cover and check and see once I get home from work.