Former zx10r guy here. I recently bought a 2008 zx14 from a private party a few weeks ago. Guy said bike had been sitting and I noticed on the initial test ride that it wasn’t revving all the way up to redline. He explained that it was probably bad gas still in the tank. I negotiated the price accordingly and rode the bike over an hour home at 100-110mph with low power. Max rpm I could get was around 5.5-6k in 6th and maybe up to 7k in lower gears (1st-2nd).
I brought it home and took the fuel pump out the next day and thought I found the issue when I found the filter plugged with rust bits. I ordered a new filter and cleaned the remaining rust out of the tank with ball bearings. A few days later I reinstalled the pump with the new filter and it redlined for the first time in neutral! I thought the problem was fixed so I decided to ride to work. Halfway through my ride I discovered that the gremlin had returned. I ordered a new fuel pump(not entire assembly) from eBay. A week later and the problem still persists but has gotten worse since new filter and pump have been installed maybe 3k-5k rpm in lower gears. Bike has a pc3 but no other performance mods that I am aware of. Can someone please point me in the right direction! I’m planning on pulling the tb out today and taking a look at the injectors.
Rpm’s increase as throttle is backed off. Max power seems to happen at the 0 mark (50%) throttle on the pc.
Bike has 20k miles and seems to be in very good condition in every other aspect.

You're on the right trail, IMO heading to the injectors. Are all cylinders firing?

You might also
check compression
plugs (probably just replace since they aren't that expensive),
check air filter interval is 11k miles so it's near needing replacement
stuck calipers
tire pressure
valve clearance (not sure Gen 2 have 15k interval, assuming that's the same for Gen 1)

We cam also assume there's no bolt on luggage or whatever that might be impacting aero?

Could be the PC3, grounds sometimes end up causing issues poor or non-running. Frankly unless you're really using the PC3, it's just a couple extra pounds and non OE electronics.

20k miles it should still run like new. Be sure to post some pics we all love 14 pics!

The black cartridge is the filter. Can't buy that without the pump. So you paid twice instead of buying new 'once.' It's on ebay because it's more a parts piece, not place into service. Injectors are clean. Back off and it has time to create pressure again.

Strange bike is check compression to see how it matches to being within spec. Valves checked, plugs and air cleaner changed out.

Ground removed on the PC is not totally disconnected from ground, being the injector has to be grounded so the loop is still closed. Remove and then test again. No change, buy a new fuel pump.

Signed,
NOLTT

* Last updated by: Hub on 3/30/2023 @ 10:47 PM *

I solved my issue two nights ago. It was a fuel pump issue. I decided to do the flow test after taking the tb out twice. The issue was not the fuel pump or injectors but instead in the secondary fuel filter? I had replaced the primary filter under the pump along with the pump. The secondary filter is in a sealed plastic housing. I couldn’t find a place to buy it online by itself so I cleaned it first with carb cleaner and an air compressor to blow the gunk back out the way it came in. It did work but only got me up to about 6k rpm so I knew I needed to do more. I took it back out and cleaned it with a bent up key ring. I normally wouldn’t clean a fuel filter with something hard and poky but it is a metal screen and I was careful not to damage it. I blew the remaining gunk out with brake clean and reinstalled. Problem fixed. Had too much fun last night racing it that this afternoon I realized I had exposed cords. Very happy that I didn’t need to pay $600 for a new pump assembly. What I plan to do next is put on a new rear tire, chain and sprockets, tank bag, touring style windscreen.

Thanks for reporting back. Pump issue with the rusty tank anshit. A poke of something at that black canister will probably clog once more. Can't really clean those. Any forced poking may send debris and close the injector holes, or be caught magnetically at the injector and score thinks up.

I tried to clean one and the powder just kept pouring out. It was futile. Had to buy the unit complete.