Need Help!

[sharur]

My newly acquired 2008 XB12scg started with some hiccups, but was running great for a while. It put many a smiles :) on my face until my recent fillup. I had run on reserve almost to the last drop. Promptly pulled into a gas station the next day, and filled up with 93. I did sort of overfill to brim by not paying attention. When I got back on to the bike, it sputtered a bit and around the bend, it died. It hesistated upon restarting, but fired up. Revving it seemed a little hard. I limped back home holding steady low rpms. I hooked up to ECMSpy to take a look. No trouble codes, and nothing unusual. I reset the AFV back to 100%, it was 90%. Did the TPS reset. I tested around the block several times.
The symptoms are - fluctuating rpms at idle, with occassional small coughs at the air box. On flat ground starts at low rpms, it hesistates before it takes off (making me ride the clutch a bit).
I have the following mods done -
a. crank-case breather re-route.
b. Removed charcoal cannister (Cal model)
c. LED turn lights with EP-36 flasher (works great thanks to this forum).
d. K&N filter - but have replaced it with OEM to trouble-shoot this issue.

Any ideas?[confused] Could I have sucked dirt in the tank since I let the fuel level go all the way down? Brand new standard plugs were installed during my last visit to the dealer. Does a fouled plug cause intermittent mis-fires and coughs?[confused]

[nitto12ss]

It sounds to me like all of this is a result of you overfilling the tank. I had a similar experience once when I overfilled and as soon as the gas level reached a normal level all was well. Take some gas out of the tank and then go ride for a while and see what happens.

[sharur]

I took a couple of spins in the neighborhood, was afraid to get stranded out there. With your response I feel encouraged to go for a "closed-loop ride" to test. Thanks.

[gbalias]

if you overfill it, theres no way for air to enter the tank to replace the fuel that is being taken out by the pump. this causes a vacuum and similar symptoms to what your are describing.

follow nitto's advice.

[hula Buell]

Very good info.Like the book says do not overfill.