81' Kz 750 keihin CV34 carb problem?

Hey guys,
Well finally got my bike on the road this week, for the first time after the rebuild. But I am having a bit of a problem with the carbs I believe. The bike starts right up cold or warm; and pulls hard up to 5500-6000rpm and starts to cut out and if you hold it long enough it comes out of it around 7000rpm and pulls hard again all the way up, this all under hard accearation "1/2 throttle or more"! But if you ease it up and past 6000rpms then crack it open it stumbles a little then goes like a mad man. I am thinking it has to be sticky slides or air/fuel mixture is not right? I took the plugs out after riding it for a bit and they look practically like new.? Oh, and I have yet to sync the carbs, but i did bench sync them.
Any help would be great thanks

Little info on my bike:
81 kz 750-4 LTD
- 4 into 1 exhaust (No baffle) Yet, but need one toooo loud!
- Dyna S ignition (wiredgeroge convertion)
- Dyna 3 ohm coils
- 83 Gpz intake cam
- Degreeable cams
- 135 main jet (stock 125)
- 35 pilot jet (stock) just order bigger pilot jets (37.5)

Yeah man I just bought an 82 ltd and had the same problem. I just changed out the intake manifolds that go to the block. Extra airs getting in.


Check it out by spraying starting fluid on the boots and the idle should climb with out the choke.

Ya ill check it out, but just thought that if air were getting past the intake boot on the engine side it would hang and rev stay up. But ill try the propane and see what happens.
Thanks

You are still using the airbox w/stock filter?

Your needles could be too lean... could try lifting needles one position and test.

Read this info about checking plugs: www.angelfire.com/fl4/pontiacdude428/Readplugs.html

Make sure to read at the end about unleaded gas. Its totally accurate, especially with high efficiency ignition systems, your plugs will stay very clean/whitish, even when jetted too rich.



Jet chart:

Ya I am using the stock air box, but I have the stock style uni filter for it.
But I going to shim the needles up a little bit and hopfully that'll help out. Finally put packing in my exhaust so it is quiter now and has a little more back pressure.
Thanks for the info!
Dylon