vm34 fouling plugs

I have been rebuilding a kz750 twin. I replaced the stock carbs with the mikuni vm34's from Dime city. they came prejetted for the kz, but i suspect they are jetted for a stock kz. mine is far from stock. velocity stacks and straight pipes. The bike flashes up with the choke or throttle slightly on. it will not start with just the idle curcuit, it will not idle and fouls the plugs. Adjusting the airscrew and/or the idle screw seam to have no effect. I must use the throttle to keep her going.

Anyone installed these vm's on kztwin? i asume i need to change the pilot jet? thanks

First things first velocity stacks gotta go unless you want to do more damage to your engine than you already have. You need filtration. ( thats a large period btw, they just dont have a big one lol). If you just intalled them i would contact dime city and tell them its not stock they should be able to help you with whats jets to start with. If you had them on there before and it worked then your jet circuit could be clogged. Good luck bro