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29mm smoothbore carburetors, #4 rich,

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07 Dec 2021 16:44 #858763 by 70zKawboy

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07 Dec 2021 17:35 #858768 by 70zKawboy
Replied by 70zKawboy on topic 29mm smoothbore carburetors, #4 rich,
Cleaned, then broken down, then ultrasinically cleaned, then baking soda blasted, then ultrasonically cleaned again, all new jets, pitot was 17.5 upped to  20, pilots up 3 sizes. were 115, upped to 122.5. Bike has henry abe intake air ceaner and vance 4 into 1 exhaust, .
replaced #2 and 3 jetblock as they were stripped, new bleader pipes, courtoust Z1enterprises.Absulutely extremely well cleaned carbs, all ports blown out with air several times during and after the cleaning process. Assembled the carbs. new gaskets. tops and bowls stainless hex screws.Installed and ran great at first idle, took off great but 3 to 5000 rpms missed real bad   acted like it was starving. go to wide open throttle. the missing stopped, but not feeling full power. but not missing, on the way letting  off wide open throttle, the mising came back consistently. at about quarter throttle. Went full throttle. killed power coasted in the garage, pulled plugs, 1 was white. 2 not quite white, no soot. 3 white but not as white as 1, #4 was fowled and sooted very bad, .

took off. adjusted the float tab out slightly on number 4, swapped thr float needle and valve out with numbet 3. , [ these were bench synced using .035 welding wire and are extremely oricisely set. I forgot to say earlier] , I also failed to say, Ive build over 59 sets of carbs, hand them to me in a oile if parts   I can build them easily, I have a set of a12 29mm on my bike I built no issues, 
went uo 1 size on the pilot from a 25 to a 27.5, and on the mains uo 3 sizes from 115 to 122.5, and my bike screams to all end with those, been on 2 years, havent has to change the olugs at all, though the bike is not lean, it rumbles just right, so, that being said, Im using my bike ti test these carbs on, It Is NOT the bike or engine or spark advancer or the dyna coils. all is perfect, its the carbs] reinstalled carbs, after installing newer cleaned up plugs, no improvement, 
These carbs haf definitely been into by simeone a few times as they tried teflon tape to repair #2 and #3 jet block, and other signs of tampering, such as 26mm mikuni float in number 3, oh and by the way, new floats installed, from z1enterprise also. Ive built so many sets but just 3 of the 29s, This is the only set that has defeated me, Im thinking the needles may have been change frim their 3rd slot, as I havent checked that yet, and ir that the number 4 jet block may have been tampered with somehow and I didnt notice, however. I ordered a new set if needles, will install 3rd slot, and also another jet block to change out the one on #4, And just hope for the best, discouraged at the moment. wondering if anyone has ever encountered such a situation and what became the solution if so. 

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  • DOHC
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  • Those Doe-Hawks really go!
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07 Dec 2021 19:38 #858771 by DOHC
Replied by DOHC on topic 29mm smoothbore carburetors, #4 rich,
Did you replace the choke plungers?

www.kzrider.com/forum/3-carburetor/61444...-plunger-replacement

If you have one rich cylinder, it's possible the choke circuit is leaking on that one.  

'78 Z1-R in blue , '78 Z1-R in black, '78 Z1-R in pieces
My dad's '74 Z1
'00 ZRX1100

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