i recently bought a 2001 f4i after installing a new fuel pump and ignition the bike fires right up, but i did notice it is building pressure in the fuel tank. if i open the fuel cap right after shutting the bike off it has positive pressure in the tank, is this normal? i have heard of the vents being blocked and sucking the tanks in but not enough positive pressure that it almost blows the cap open when i turn the key to open it ?

 

I don't think it's normal, wonder if it could be the fuel pressure regulator? Is your bike a california or euro bike w/ the evap canister?

 

i thinking the same thing chambers. does anyone know what the fuel pressure should be on this bike? im going to try clearing the vent tube for tank as soon i can locate it .. i can make 4 wheels fly but this 2 is new

 

It's 50 psi at idle, is your bike a california or euro bike? If you don't have a manual you can download one here http://www.stephygee.com/f4imanual.zip.

 

it is not a cali or euro bike. i ran a wire up the vent tube in the tank and it seemed like it may have fixed the problem. till i rode it today for the first time. i rode about 6 miles and when i got home the pressure was back in the tank. the only other problem i noticed is when the bike has been run and i shut it off, when i start it back up it appears to be running really rich if the bike doesnt stall from idling so low, i barely crack the throttle about 1000 to keep it from stalling,it idles up to about 2 thousand and then drops right back down to the 1300 idle and idles fine and no longer runs rich. this only happens at start up hot. when i start it cold it starts right up at normal idle runs up to 2000 rpm for a few seconds and drops right back down to the normal idle.

 

Gonna have to drain the tank and then blow out the vent. It is not normal for the tank to build pressure. Might as well clean the petcock filters, while the tank is empty, too.

Ern