[Ryan Magner]

The Issue: Ran hard for 80 miles in the morning. Stopped to take a break, got back up to leave, bike surges at ~8 k rpm. Bike revs through until it hits 8000 rpm then it feels like fuel cuts. If I hold the throttle on, it will buck, going on and off every second or so. No FI codes.

So Far: I have changed spark plugs, checked coils for impedance and spark, checked air filter. Took the fuel pump out, cleaned out the screen. Did the inspection on the pump per the manual: fuel pressure and flow rate were both in spec.

I feel like I've done the easy stuff so far. Anyone have any other things to check before I go insane? I do have an ebay fuel pump on the way that I will try in a few days.

Thanks

 

[Nedrobmas]

I have pretty much the same bike(Zx6RR), same problem, but haven't rode in a while. It might be just that the fuel pump, I guess we'll see when you change it. Update us on what happens please.

 

[RJ2112]

If it's happening at 8K and above, I would be looking at the secondary injectors, or anything else that comes into play at WFO. Secondary butterflies, vacuum leaks, etc. If it happened suddenly, something clogged, or came loose.

 

[Scorpi0]

Yup. Either a weak fuel pump or bad secondary injectors.

 

[Ryan Magner]

Pulled injectors (03' only has primary injectors I believe) and cleaned them. Still had the issue. Put in half a tank of new gas, issue was gone for about 10 miles. Shut the bike off and went to start again, now the bike is stalling at idle! I'm thinking fuel pump.

 

[Nedrobmas]

Put in half a tank of new gas, issue was gone for about 10 miles. Shut the bike off and went to start again, now the bike is stalling at idle! I'm thinking fuel pump.

Had the same problem, is your choke pulled all the way in?

 

[Ryan Magner]

Changed the fuel pump. Issues persists. Start checking sensors at this point?

 

[Scorpi0]

Youre correct. No secondary injectors on the 03/04 models.

Before u go any deeper, check and make sure your exhaust butterfly valve isnt staying stuck in the closed position.

Also, do u have a power commander or something similar on the bike?

 

[RJ2112]

OP, does this happen with the bike in neutral, or only when riding?

 

[Ryan Magner]

No exhaust butterfly valves that I could find on the bike. Has a power commander 3 as well as a shorty 2 brothers slip on. This only happens when riding, I can rev the bike to redline (or 13k, I'm not trying to legit redline my bike with no load) in nuetral. Also checked compression for shits n' giggles, no problems there.

Appreciate all the help, this one is kicking my ass!

 

[upland117]

Did you find out the issue? Might be worth disconnecting the Power Commander to make sure it's not the issue.

 

[bart636]

Try removing side stand switch, join wires together and go for a run.

 

[Nedrobmas]

When was the last time your valve clearance was checked? Any recent maintenance done?

In doing minds now and notice a lot of black deposits on some of the pins on the cylinder head assembly. About 8(2 ex #1&4, 2 in #1&3) of them out of spec in millimeters. If you go this route, let me know your results.

 

[bart636]

bypass your side stand switch, it worked for me and many others!!!!