GSXR WP - 3 - 6000 RPM hesitation, dying then takes off

[NorthernBloke]

GSXR1100WP --I suspect this might be similar to the Slingy Carb issue with emulsion tubes from what I've just read, anyway here is the story.   Bought an 1100wp cheap that needed a few chassis  jobs doing so got these done and went for a short test ride which was fine. Since nothing fell off or leaked over the tyres I went out again and opened it up a little and it absolutely flies but after 10 mins riding i.e when its properly warmed up and off choke there is a real hesitation from around 2500 to 5000 revs roughly so bad that I thought it was actually conking out on me but I dropped it a gear and gassed it and eventually once the revs got higher it chimed in and ran on all four again, when it does it it feels like its running on 2 cylinders its that bad.

On choke it runs as expected nice and smooth and pulls and revs normally, then off choke its smooth up to 2,5 to 3k revs and rough until 5 to 6k revs and then runs normal higher up.

Given the state of it I doubt its had any meaningful servicing so will go through it from one end to another, but was just wondering if this is a common issue?

cheers in advance

[Jaydee]

Could be a gummed up slow circuit. Having it on choke bypasses the slow circuit. At 5k revs the bike would be running on mains.

As you state 'bought cheap' it sounds like it was lying up for a while. Only real course of action is a full tear down and ultrasonic cleaning, servicing of the carbs. While you're at it do the valve clearances and fire in some fresh plugs too.

[NorthernBloke]

Yep all of the above is on my to do list, which gets longer each day !

[NorthernBloke]

Update;  It's in lots of bits now so will be a while before I can start it and test it but I've striped the carbs and they are already very clean I've not found any blockages but I have found worn needles and the settings don't match any specific countries setup listed in the manual? The bike has previously been imported as it came with a KMH speedo, so I'm assuming European. 

Here's what I've got BST40's, with 127.5 mains and 40 pilots and the pilot screws were all 2.5 turns out.

The Emulsion tube id's are 6996 p 2

Needle jets are 6ZD13's with the clip on the 3rd slot

The trouble is that this actual combination isn't shown in the manual, having said that its been this way for quite a while I imagine so not sure if its anything to worry about, I'll probably price up new needle jets to replace the worn ones and put them back together.

Is there anything obviously wrong with the above? and here is a screenshot of the details from the manual.

 

[dupersunc]

Classic blocked pilot jet or pilot jet circuit.

Get the carbs ultrasonic cleaned, rebuilt with correct float heights etc. 

You're on a hiding to nothing till then.