Decel pop ...STILL

Can anyone tell me what carbs I have? 1980 kz1000 B4, I've seen pics of 28's and 29's and have not seen my carbs,no accel pump,17mm drain plug,I'm thinking that I'm still running lean and want to change the pilots,currently running 17.5's

Those look like 29s to me.
Here are some pics for comparison


Intake side


Right side while on bike

As for the pilots I cant say ?

Regarding decel pop, before changing to larger pilot jets, would first try slightly enriching the pilot circuits by turning each pilot air screw in clockwise say 1/4~1/2 turn, and test run.

Also, decel pop may result from a too low fuel level or an imperfectly clean pilot circuit or incorrect sync or air leak.

Good Fortune!

Make sure fuel levels are right, check with clear tube.

stupid question, but could it be the emmission ports causing to pop on decel?? only reason i suggest it is mine did the same till i plugged them.

If you don't have an intake or exhaust air leak, the only other cause for decell pop is excessively lean pilot jets.

Thanks Guys I pretty much covered the air leaks,new exhaust gaskets and new carb holders,float level @ 3mm,emissions plugged,when I pull the choke on just a hair it doesn't pop,so I'm thinking of going up to 20 pilot I'm already runnin a 17.5.and thanks Patton and moneypit for the pics they are a big help.

Powerstroke_fan wrote: stupid question, but could it be the emmission ports causing to pop on decel?? only reason i suggest it is mine did the same till i plugged them.

Seem to recall others having reported unplugged ports caused popping exhaust.






Good Fortune!

Not a stupid question at all,after your post I gotta thinkin,the previous owner had connected both hoses with a T and to a small pod filter,I wouldn't have thought about it, BUT I pulled the filter and put a 3/8 bolt and clamp!Whatta ya know no more DECEL POP.I'm gonna pull the tank tomorrow and replace the hose with just one piece.Thanks a bunch this has been drivin me crazy!And Thanks Patton for the emission pics.

glad to help. what i did is pull the valve cover off and go buy some plugs and tap and plug the emission ports in the head.i used to have a one piece hose and it still poped.I had to plug them.

Hey Guys I've seen everything now, I thought that I had been over every inch of this bike,come to find out I guess I haven't, check out this contraption that the previous owner did!2 pieces of 5/8 hose to a 3/8 tee with 3/8 fuel line going into the 5/8 hoses and a small filter pod. I replaced the hose with 1 piece of 5/8 heater hose and ALL the decel pop has went away.If any of you guys are @ the Vintage Japanese show in Jefferson PA in August I'll buy ya lunch!Thanks again

are we talking steaks or bologna? lol jk glad you got it straightened out.