Help 84 kz700 with bs34 carb

Hello I've been working on my bike for weeks and she's in good running condition now idles very well revs well and all that however I have one problem I've been trying to figure out and would like some help please. When I got the bike many mods were already on the carb which I had to identify one by one to get her to run properly. When I got the bike, I believe the PO installed a dynojet kit because when I checked the slide it was drilled out, had the air correctors installed for pods and needle was adjustable which in this year model shouldn't have an adjustable needle. Changed the pods to k&n instead of the Chinese ones he had on now she runs great except for one issue.

The bike revs clean but once it hits 6-7 k rpm, there like a temporary surge but I could rev past it and she goes all the way to redline. What could be the cause of this? I just followed the dynojet instructions, told me to put slot and spacer in 4th slot and use dj165 main jet. I wish I can remove the kit installed but the slides were already drilled out and dynojet needle was already in it. Bike has stock exhaust and k&n pod filter. Airbox is non-existent.

DynoJet kits are not perfect, but close. For example on my ZRX1200R I had to use a Mikuni main jet 1 size smaller.
At that rpm raising the needle further may cause issues at lower engine speeds. I would try one size different on the main jet first.


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Even without the DJ kit, you would have to be playing the jetting game. I suspect Nebr_Rex is correct about the main jets. One size up may solve the problem.

Here is a simple method to get the carbs dialed in.

www.factorypro.com/tech/tech_tuning_proc...igh_rpm_engines.html