I wish I had come across this thread before I spent about 16 hours troubleshooting my wiring. I knew something was wrong. This bike wouldn't pull over 9k RPM. After digging for days I found a wiring schematic. Found a bunch of bastardized wiring and fixed it (headlight bypassed cause starter button failed and all the lights were Mickey Moused). Then found voltage problem at STVA. Called local Ride Now and they wanted to sell me a whole rack for something like $800. I looked on EBay and couldn't find just an STVA, so I tore it apart and found a burned trace and 2 broken solder joints from plug to PCB and the pcb was cracked. I hard wired it all back together and left a bit of slack in the wiring, took about 5 minutes. Ran down to Ace Hardware and got some 3mm screws and teflon lock nuts. Installed it back on the K5, No more F1 code, It will pull 14k RPM now with no problem, no flat spots in the throttle anymore. I was almost to the point of thinking the problem was that this thing had been rode hard and put away wet one to many times (which is probably the case knowing the previous owner), but it actually runs damn good. Geek, you rock man, I should check the forums before I try to fix any more gremlins in this bike. Would've save me a hell of a lot of time.