gsxr 750 acceleration problem

2000 gsxr 750.  This bike is completely stock with the exception of a Micron slip-on exhaust.  Starts and idles fine.  No F.I. light.  There is hesitation when you blip the throttle, and if you give it too much too fast it dies.  Bogs in lower revs.  Gets bad at around 4k,  and then rips above 5k.  I haven't tached it out to see if problems exist on top.  New plugs.  Removed and cleaned fuel pump housing, filter, lines, pressure relief valve,  fuel rail, injectors, and air filter.  Some surging in lower revs also.  Performed flow check on fuel pump and am getting about 1000 ml of fuel in 30 seconds.  That's about 200ml low compared to the maintenance manual figure of approximately 1200ml.  Do you think this could be my problem, or possibly elsewhere?  A new pump runs over $500.  Any useful information would be greatly appreciated.  

Check the screen in the fuel tank petcock. You definitely have a fuel starvation problem.  

If you read my post, it says that I already did that.  Twice actually.  Battery voltage is 12.55 volts.  

Sorry, wasn't sure if the 2000 model had an inner-fuel-tank-mounted fuel pump or outer unit.

Is the 1200ml figure you listed the minimum output specified in the service manual on the fuel pump flow test? If it is, I'd say that 200ml/30 sec. less is a definite sign that something isn't right there. Is there a way to check the fuel pressure regulator to ensure that it's working properly and isn't restricting flow in any way?  

Sorry.  I don't mean to come off like a jerk.  I do appreciate the help. The pressure regulator by itself is an outragous 200+ dollars.  I could try to rig up a direct reading pressure gauge.  What do you think of capping the regulator so it can't relieve pressure and test again?  The maintenance manual says approximately 1200ml in 30 seconds with a fully charged battery.  I have had a meter hooked up while doing the output check and the battery holds fine under load.  and yes the 2000 model is internal in the tank.  The pump has to be disassembled to get at the filter.  I want to be sure before I go and change the pump.  

No worries, no offense taken.

Yep, prices for separate EFI components are enough to make you want to go back to carburetors.

Is there a specified test/reading for fuel pressure in the manual? I think that test would be the key, because then hopefully (not sure how everything is plumbed) you could isolate both the pump and the FPR to find the culprit. The symptoms definitely point to a fuel starvation problem caused by inadequate fuel pressure.  

Sounds like the micron has affected the mixture (back pressure)

Try with the stocker zaust back on....................

BTW: Tap it out at top RPM to diagnose a pump problem.................  
brmbrmmm

A slip-on exhaust won't affect a/f mixtures enough to cause the symptoms he's describing (especially a Micron, which is one of the quieter mufflers sold). Modern mufflers flow well enough that even going with a straight-through race baffle does little to affect airflow. It's the rest of the exhaust that will make the biggest difference.

It's much safer to diagnose pump problems while the bike is at rest, instead of risking burning valves and pistons from running too lean under load due to inadequate fuel pressure.  

Ya 0 for 2 kento

Because the bikes are set up for emission tests at 60 or 100 klm/hr, they manufacturers lean them off to comply.

If the problem is happening around 4K, the micron can cause it

Chuck one on a dyno and see..............  
brmbrmmm

Not lean enough to cause bogging below 4000 rpm and the engine to choke if you blip the throttle with just a slip-on muffler. A slip-on will not make enough of a difference in flow to upset the a/f ratio that much.  

Hey Kento.  I am pretty sure I am going to swap the fuel pump.  I was just wondering what you think about carbon tracking.  If it was that I would think it would do it at higher rpm also.  There seemed to be some light sign and I tried to clean them what I could but it didn't make any difference.  I ran it a little bit last night and it seems to go fine at first, but repeated attempts get worse.  If I lug it a bit and go again It seems to improve a bit on the first go.  Instead of nickle and diming it I was going to replace the whole pump assembly.  Let me know what you think.  Thanks.  

Fuel pressure is 44 psi.  Manual states approximately 43 psi.  Pressure comes up pretty quick.  Manual states checking by way of a check bung on the fuel rail.  There is no such thing on my fuel rail.  only straight pipe between the injectors.  I will try to stop off and get a T fitting and try to rig something up so I can monitor the pressure while running.  

I got my test set-up ready to go.  Its to late to be making noise tonight but, tommorrow should yield some good information.  

Is there a way to isolate the FPR? That would get rid of one other possibility.  

Good pressure while running.  No dips.  Today or tommorrow I am going to check the injectors and the coils.  Again, it is only in the low revs.  I will keep you posted.