K75 Sunday puzzle

[nortonbrian]

O.k. moto bricks, here's one for you. Purchased a1992 K75, it had a low side ,mainly cosmetic.
Rebuilt brakes, new tires and battery.
Changed fuel filter, injectors cleaned, throttle sync. Replaced fuel hoses and breather pipe. Fuel pressure normal.
Bike ran perfect for 200 miles and then showed symptoms of fuel starvation, running out of gas. Checked everything out, flat spot gone but now have an intermittent misfire.
Bike starts and idles great, but from 3,000rpm up it staggers along.
Swapped out coils, ignition box, HES, EFI,spark p!ugs.
Is there a way to feed the ignition direct from the battery and bypass wiring switches etc?
I am ready to try anything at this point, wish it would quit, easier to locate the problem.
Thanks
No arching from plug wires

[TimTyler]

Try some Heet.

How were your injectors cleaned?

[Scott_]

Do the '90's k75's still have the air flow meter?
tps switch adjustment?
coolant temp sensor?
general vacuum leaks?

just some other variables that can affect fuel delivery.

[K75RT Keith]

Do the '90's k75's still have the air flow meter?    YES  If yours is stuck it would be running lean or rich
tps switch adjustment?   YES But that likely wouldn't be in play at 3000 rpm
coolant temp sensor?    YES
general vacuum leaks?  NO MORE OR LESS THAN ANY 20 YEAR OLD K-BIKE  Air leaks would also show up as a wandering idle

just some other variables that can affect fuel delivery.

How much fuel is in the tank?  If the pump isn't properly seated and your running it low on fuel , it can starve itself.


Check your Fuel filter again and inspect the pump and tank internals for debris.  If the rubber vibration collar has started to disintegrate, it could show as these symptoms.   When was the air filter replaced

[Motorhobo]

Crankcase breather hose...don't all k75s have the AFM? Hope it's not that...that's a bitch to out and back in again...at least I have terrible memories of that.

[nortonbrian]

Injectors sent to Mr. Injector, all new hoses, including crankcase vent. This is a cutting out, like hitting a kill switch on a dirt bike.
I am going to bypass the wiring from the battery to the ignition switch and start from there, maybe a break in the wiring or?

[Motorhobo]

Have you tried unplugging the EFI brain, spraying come contact cleaner on the contacts, and plugging it back in? General ignition weirdness can sometimes be fixed that way. Once my bike cut out on the NJ turnpike near Newark with dog in sidecar...Not good place to be a sitting duck -- that fixed it.

[nortonbrian]

E cleaned all connections and used dialectic grease on all connections.