I have an 06 kawasaki brute force 750. It cranks and idles fine, however after I get about quarter throttle only one cylinder is firing. I have cleaned out the carbs, added new spark plugs and tried different cdi boxes when the same results. Has anyone else had or seen an issue like this.

 

The first thing you need to do is narrow it down to fuel, spark or mechanical.
Does it get spark?
Does it get fuel?
Did you take a compression test on it?

 

It's most likely that one of the plugs is fouled due to choke plugnger being partially open and it is not firing. The 750 has a single choke cable that spilits into two just before the carbs. The choke system is not really a choke on the 750. It is actually a fuel richening system on the carbs. There are two small plungers that provide excess fuel to each carbs whenever the choke lever is pushed to ON position. The routing is very critical so that it is not binding or twisting which could partially open the choke plunger providing excess fuel to one of the cylinders. Check the choke cable routing and visually inspect the choke plungers as you open and close the choke lever.