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Hey everyone! Im running a 1978 KZ1000 LTD B2. I'm looking at putting a set of 34mm carbs off a '93 kz1000 police bike. I have 26mm CV carbs on it now.

i know i will need new intake boots but is there anything more i will need?
And has anyone done this swap?

i have a stock setup now other than a V&H 4-1. I plan on doing pistons (ether stock bore 10.25:1 or 1075 10.25:1) and pods. still going to be a daily driver but im looking to give her a bit more snap. Is this going to be a good setup for my stock bike and can they be tuned to match the future work?
 

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KLR`s and BBQ`s
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not sure if this is relevant, but my 82 kz1000 with the same carbs has a vaccuum operated petcock, so I assume the cop bike has the same. Again, I'm not sure but am wondering if this will effect the fuel levels in the float bowls since you don't have a vaccuum pet
 

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Navy Vet Search & Rescue
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It doesn't matter what type of petcock you have. If a vacuum petcock is working properly (diaphragm not torn etc) then the vacuum appiled to it is not a drain on vacuum. It would be like you sucking on a straw that is plugged at the other end and doesn't allow any flow. So if everything is working properly there will not be any difference regardless of petcock type.
 

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You say you have 26mm "CV" carbs on there now??
Even the 750 fours use 34mm CV carbs (both Kehein and Mikuni).

CV stands for "Constant Velocity" (or some people say Vacuum), they have a rubber diaphragm on top under a largish square cover and a butterfly throttle blade.

BS 34 Mikuni's would work great on your bike. There's a fellow that does carb restoration and rebuilding in Texas called Wired George, people seem to regard his work pretty highly, and he recommends the BS34's for the 1000's,
 

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KLR`s and BBQ`s
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i love how some people say bs34's are absolute trash, and others say they are great. I personally have them and love them, but what do i know.
 

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bs34's arent trash.....just a little more finicky and replacing rubber diaphrams when they go is a pricey deal.....plus they rely on vacuum to operate properly...pods dont help the vacuum situation......i ran a set....they work.....29 mm smoothbores are a way simpler carb and in high demand for a reason....they are pricey, but they get the job done well with simplicity....thousands of drag racers cant be wrong....
 

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Navy Vet Search & Rescue
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Yea 29's would be nice but at $450 a set (if your lucky) they are a little expensive compared to the value of the bike.
 

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.thousands of drag racers cant be wrong....
Yep, and that's the point, exactly how many people drag race their KZ1000?? So most people wind up installing the 29's on a street bike where the BS34's would be a much better choice.
 

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Yep, and that's the point, exactly how many people drag race their KZ1000?? So most people wind up installing the 29's on a street bike where the BS34's would be a much better choice.

why would bs series be a better choice over vm series? i m just wondering...
i ve run both and i prefer the vm s.....
 

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why would bs series be a better choice over vm series? i m just wondering...
i ve run both and i prefer the vm s.....
I assume you are an aggressive rider, because that's the only type that I can see saying they prefer 29's over BS34's on the street, assuming both are set up right.

Some people just think they look cool.
Some just want to be able to tell others they have "29's" on their motor.
Some want 29''s because of all the people saying those are the carbs to have.

But most people that have 29's won't say anything bad about them because they're afraid everyone is going to tell them they don't know their backside from a hole in the ground :)

Tests have shown that even though a stock 29mm Smoothbore carb outflows stock 28mm mikuni carbs, the stock 28mm carbs actually outperform the Smoothbores at the drag strip, because the Smoothbores have very poor low speed response due to poor jet signals.
Not to impressed with the source of this one> Campbell X-Pipe ® -- 4989 Holt Blvd Unit #2, Montclair, Ca. 91763



BS34 carburetors out perform VM series aftermarket smoothbore racing carburetors in almost all street applications
wiredgeorge motorcycle carburetors - Vintage Japanese Motorcycle Carburetor Sales, Rebuilding and Restoration - Carburetor Sales

And Kevin Cameron in his Sportbike Performance book.
 

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all i know is when i twist it with a 10.5 1075 with 2x cams and 29's, after 5k the scenery starts going by at a pretty good rate.....my head is going out for mild port work next week.with that and the 14 tooth front sprocket, should be a runner.......read all ya want.....my seat of the pants opinion says 29's are the way to go.....just my .02.........by the way....Happy New Year.!!
 

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GHOSTRIDER
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26s are slide needle carbs. (aka REAL carbs) Bypass the 34 CVs ENTIRELY and find a set of 29 smoothbores. They bolt RIGHT up, allow you to use silly filters (K&Ns) and you don't have to change the right switch housing.
+1:wink: Finding 29s that arent wore out with stripped jet blocks or any at all for that matter is the trick!
 

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GHOSTRIDER
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Heres my take on the carb issue. A set of well tuned 26mm carbs will smoke the BS34s because of their tunability. The key is that a rider who understands and (wants) to tune those carbs will out perform any later model riders TM or BS carbs who dont/wont understand flow and burn(mix). The KZ-1000 is a drag bike detuned for street use! The potential is there for those who know how to tune them! Im not knocking BS34s, Im just saying I can squeeze more out of my 28s.:wink: 29s are practically non-existent now days, the 28s are not.
 

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all i know is when i twist it with a 10.5 1075 with 2x cams and 29's, after 5k the scenery starts going by at a pretty good rate....!
Ya know, that's what I've been saying, if you're an aggressive rider then you'll like them, if you're a normal rider you'll like the BS34 better :)

Course, when I open up the 33mm throttle bodies on the 750 Turbo, after 5k the scenery starts going by "really" fast :D
 

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+1:wink: Finding 29s that arent wore out with stripped jet blocks or any at all for that matter is the trick!


i found a set on ebay that were bought new and had 1k miles on em and had been put away for years....i paid dearly for them and when they showed up
they were as advertised...still had little yellow dabs of paint on the screws holding down choke shaft..as far as i can tell, unmolested.....they are out there......just extremely pricey......anybody know what a set of them new went for in the 80's?......
 

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GHOSTRIDER
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i found a set on ebay that were bought new and had 1k miles on em and had been put away for years....i paid dearly for them and when they showed up
they were as advertised...still had little yellow dabs of paint on the screws holding down choke shaft..as far as i can tell, unmolested.....they are out there......just extremely pricey......anybody know what a set of them new went for in the 80's?......
:lol: Go ahead and rub it in......
 
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