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Eng. Miss RS34 carbs

803 Views 9 Replies 4 Participants Last post by  TrialsRider
Hi guys. i need some help to get rid of a miss in my KZ 900 eng.
I'm sure it is the carbs and not electrical. i have switched coils and wires and the miss stayed in the same cyl.
I have cleaned the RS34 carbs a few times and the miss has moved to dif, cyls. after cleaning.
During the last cleaning i discovered the pilot screw O rings have degraded and some bits may have gone into the pilot circuit? I replaced them with new.
I will clean them again and focus here.
I have been testing where the miss is by using a temp gauge on the header .i can tell which cyl is running hot or cool, so i can know which cyl is missing/starving for fuel.
what I just noticed just now is that if i hold my hand lightly in front of the carbs bell mouth(air filters removed) i can feel a slight air pulse on #1 , a very strong pulse in #3 almost like its spitting back, and no pulse on 2 and 4?? At the header, the temps are like this, 1= 300* 2=215* 3=255* 4=175* don't pay attention to the low temps its not completely warmed. just that #1 is running best and 2,4 are worst. they should all be a similar temp.
What is this difference in pulsing telling me??

compression and valve clearance is good is good.
76kZ . gusset work,1200CC.Mukini RS34"s.,ported by Larry Cavanough Racing,1.5mm.over intakes,.424" lift cams ,under bucket shims, pods, Caron Header, undercut trany, Billet 2nd, Earl cooler, Dyna 2000 with 2.2 ohm coils,05 ZRX12 rear end and seat.ZX9 front end.
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KZ900 always had nice long stacks on the airbox, I don't think you're giving it much chance if you are running open carbs and even less chance of improving carburetor efficiency by blocking the intake. Put the almost 3 inch long stacks that came on it back on and it might work a little better.
Don't forget he's running aftermarket carbs, so the airbox runners won't even fit.

That being said, they may need a thorough soak in an ultrasonic cleaner. My CR29s took several passes before they were cleared up of blockages.
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