bike backfires

hello i have a kz900 with a '77 kz1000 motor in it(bike made to look like a a1 1000)i'm running pods on the carbs and a vance and hines pipe--when you fire the bike up,barely needs any choke--take off is fine,but when the bike warms up,starts to backfire--i know it is running a little on the rich side--but when you get on it(i go easy on these old babies),it takes off like a rocket--no running probs-just the backfiring issue--any ideas as to what to do?--any help would be great--it should be something tiny--

In order to get the carbs spot-on, you need to make sure that the valves are properly adjusted and that the cam chain is within spec. Also, the ignition system needs to be up to snuff - good spark? Advancer working properly? Good battery?
Last are the carbs. They need a good inline filter. Check fuel height by the clear tube method. Synch and adjust.

There are good tutorials on these things in the file base (there's a button near the top of this page). The factory shop manual is mighty helpful as well.

changed the fuel filter--i'm stumped--went for a ride--smooth idle,smooth ride--but when you let off the gas--and downshift--that's when it starts talking to ya--then it stops--??:blink:

Hello, kz73, and WELCOME to KZr!

Exhaust popping on deceleration sometimes results from too lean carb pilot circuit.

Would enrichen pilot circuit and test ride to see whether popping is affected.

Side-located pilot air screw (KZ900) would be turned in clockwise, say 1/4~1/2 turn.

Bottom-located pilot mixture screw (1977 KZ1000) would be turned out counter-clockwise, say 1/4~1/2 turn.

Good Fortune!

"Exhaust popping on deceleration sometimes results from too lean carb pilot circuit.

Would enrichen pilot circuit and test ride to see whether popping is affected.

Side-located pilot air screw (KZ900) would be turned in clockwise, say 1/4~1/2 turn.

Bottom-located pilot mixture screw (1977 KZ1000) would be turned out counter-clockwise, say 1/4~1/2

turn." Patton

If this corrects the popping, on a KZ1000 B4, is there something else needing done?

hello i changed the plugs from b7 to b8es and :woohoo: man,what a difference--doesn't backfire anymore--and i rode it around enough to get good and hot too--also reset the idle down to 1,000-man,what a difference--checked the plugs though and they are still getting sooty--wonder if setting the pilot(idle)jets would remedy this--i know a lot of this is trial and error when you add performance mods to any machine,but you guys have been great with the help as i don't like damaging these aging superbikes-going out to ride today-let you know how it doesB)