2 dead spots in rpm band?

ok i have a 81 xj650 maxim has pods and open header and has been jetted and plugs look great. If your riding and you take off it will have power from idle to about 3200 then it will lose power tell about 3800 and then take off with alot of power it does this at any throttle. then if you are full throttle and it gets up to about 6500-7000k it will pop then just keep going. im really trying to fine the one at 3200-3800 cause thats where i ride at. thanks i know my writing sucks to read

 

sounds like the needle circuit. Is it a full jet kit or stock needles? The 6500 hiccup is the main jet circuit. The best way to do this is to get it on a dyno.

 

How completely "done" were the carbs prior to all the mods and rejetting?

How did you set the float levels?

Another thing that can cause the symptoms you're describing is bad throttle shaft seals that're only bad enough to reveal themselves when the throttle shaft rotates a great deal.

When trying to sort something like this out, you have to start with everything else 100% or you can easily be mislead by your results.

Are your valves in spec?

 

stock needles and float level i left alone and i think the shaft seals are bad cuz when i come to a stop the idle will hang for a couple sec then drop down where it needs to and for the valves i havent checked them

 

Float levels can cause "hanging idle" issues; as can an out-of-sync condition and you can't properly sync the carbs until the valves are in spec.

Furthermore, at the mileage that bike is at, you'd better check the valves pronto before you burn one.

You gotta do this right, and IN ORDER, or it's never gonna run close to right; especially now that intake and exhaust mods have been added to the mix.

Valves first.

 

I just got this gopro hero and made a small vid so you guys could hear what im talking about i was alittle high in the rpms but its right as i hit the throttle hard. turn up you speakers and listen. thanks again guys

http://www.youtube.com/watch?v=_3EMawWy-WY

 

When you "Lose momentum" like that ... the problem with the "Dead-spots" is related to:

Insufficient MAIN >AIR<

At Wide-Open-Throttle, ... a Vortex occurs at the Intake Horn.
This Turbulent activity LOWERS the Air Pressure at the Atmosphere Vent.

Upon the Lowering of Pressure at the Atmosphere Vent, ...
The Diaphragm becomes more difficult to collapse.
Causing the Piston not to fully and quickly rise to supply more Fuel to the Mixture, ... the Dead Zone ...

When it does catch-up, ...

The FUEL Exiting the Center Emulsion Tube, ...
Is not drawn-up and out with a Strong Siphoning because Main AIR is starved.
The reduced Main Air results in a diminished FLOW through the Emulsion Tube Ports, ...
Reducing Fuel Flow
Failing to Atomize Escaping Main Jet Fuel
causing Main Jet Supplied FUEL to enter the Intake Stream in a Rivulet form as opposed to a Atomized SPRAY, ...
Thereby causing the Mixture which reaches the Combustion Chamber to be in a, ...

Power-robbing, Non-explosive, Lean-condition.

 

Ignoring the need won't put the valves in spec. Do that first. You're approaching the "danger zone" mileage-wise.