28mm Mikunis Better Than 29mm Smoothbores?

79MKII wrote:

Street Fighter LTD wrote: Started out new in 78 with 26mm on my LTD My LTD would out pull down low my best friends 78 Z1R with 28mm stock carbs then he would start pulling on me and win everytime... 1/4 mile runs
I went to 29mm SB carbs and now could beat him every time. These 2 bikes repeated these races at least 1000 times
Then he added a Winning Header and he was now dead even every time.
I then added a Yoshimura pipe to my bike and was again the winner every time
Both to this point had stock motors. so carbs and pipes were only variables.
Hope this helps
Dave

That is awesome info right there! Real world test results....thanks for sharing.

I agree excellent info ......... How many bike length's are you talking? ....... you say he beat you then you beat him after the carb change hoping you can remember by how much.... Did the same thing with a number of friends and we got very consistent at it but by the time I bought my 29s they all either went bigger or sold theirs off.... I also had already put on the V and H header before so I didn't know what difference that made either.

pete greek1 wrote:

strum wrote:

pete greek1 wrote: No way are they worth 650.00, or are 29s worth 600.00 - 800.00 that people pay for
why spend that kind of money on a set of 40+ yr..old carbs that are hard to find parts for, when you can buy a brand spankin knew set of RS 34s for around 600.00, & they'll out perform both the 28s or the 29s, that's just my opinion
Pete

this was kind of what i was asking in another post a few weeks ago.. since i have no experience with the RS34s i was wondering if they were
a better way to go. Just out of curiosity. what can I expect if i bought a set of these for my 1000 shaft? it has the 28 pumper now
better performance, easier to tune, better fuel mileage ? money wasted ?

I don't think RS 34s would work well on a stock motor, & non ported head, IMO, bigger is not always better
Pete

A popular reputable engine builder in Florida (Joe H. of PSP in Orlando) recently replied to me with a good rule of thumb when it comes to carb size vs. head configuration compatabilities....."When you compare how much the carbs of a certain size will flow, it doesn’t make much sense to pair it with a head that is designed to flow a lot more, or equally vice versa. If you look at the flow area of a 39.6mm valve you have to subtract the valve stem area and the difference in the size of the valve OD and the size of the ID of the valve seat to come up with the flow area. 38mm carbs would be the optimum size for this sized valve.".....This reply was concerning a big bore engine build configuration posibilities. I have 38 RS Mikuni's and wanted a compatable head built to match those particular carbs for my 1327. He assured me it is a good rule of thumb to follow when deciding what size carbs will produce optimum performance for any given head configuration. Judging by that info, 34mm carbs on a stock(ish) head sounds like a bit of overkill to me also as Pete alluded to, however maybe a good enough tuner cld make it work......................Mike

Vroom-vroom!!!

KZB2 650 wrote:

79MKII wrote:

Street Fighter LTD wrote: Started out new in 78 with 26mm on my LTD My LTD would out pull down low my best friends 78 Z1R with 28mm stock carbs then he would start pulling on me and win everytime... 1/4 mile runs
I went to 29mm SB carbs and now could beat him every time. These 2 bikes repeated these races at least 1000 times
Then he added a Winning Header and he was now dead even every time.
I then added a Yoshimura pipe to my bike and was again the winner every time
Both to this point had stock motors. so carbs and pipes were only variables.
Hope this helps
Dave

That is awesome info right there! Real world test results....thanks for sharing.

I agree excellent info ......... How many bike length's are you talking? ....... you say he beat you then you beat him after the carb change hoping you can remember by how much.... Did the same thing with a number of friends and we got very consistent at it but by the time I bought my 29s they all either went bigger or sold theirs off.... I also had already put on the V and H header before so I didn't know what difference that made either.

Been a million years but all our races were pretty close. We are talking a couple bike lengths when I talk about winning or losing to the Z1R.
Then we went for big CCs head , clutch work. Slicks, wheelie bars ect...
Then the Z1R went Turbo and I did too
Dave

No eBay APP ID and/or Cert ID defined in Kunena configurationThese smoothbores will make your bike faster, (because they're chrome), :laugh: :laugh: :laugh:

Pete

No eBay APP ID and/or Cert ID defined in Kunena configurationHere's another price for 29sb's (same seller) that will make you giggle 'til tears run down your cheeks...
...........................................Mike

Vroom-vroom!

while we are on the subject..i looked at those smoothbores on ebay..the chrome one would worry me a little.
and the others my be ok but for crying out loud why are they so expensive?
Is there not any where a guy could pick up a set at a fair price?

No eBay APP ID and/or Cert ID defined in Kunena configurationheres anewly listed set . I emailed the seller and told him these are NOT 29mmSMs

Find a set for normal, reasonable money? Put an ad in the paper, an ad on craigslist, a sign in your yard, looking fir bike parts, sift thru the hundreds of turds and hope to get lucky, or stumble on a set nobody knows what it is (better be quick and click buy it now if it's on eBay.) or, just realize they aren't worth the money and forget about it.

A member here, bozo adapted gsxr carbs (i think) for a decent boost in performance, and somebody put zx7 carbs on a kz650, both are available a lot cheaper than smoothbores.

And about the seller listing those as smoothbores... He don't care! Do a search for Z1 900 parts and see all of the purposefully mislisted kz650/750 and 1000 parts tagged with words like z1 kz dragbike turbo etc etc. they are listed like that to generate hits and snag a bid or two

Looks like I need to sell a set :woohoo:

Aren't the KZ models supposed to have the 1.5 cutaway?

Yes. The Z1 came out with 2.0 but went to 1.5. It was too rich at the bottom. That's the problem I'm having with my 33's.
Steve

floivanus wrote: Find a set for normal, reasonable money? Put an ad in the paper, an ad on craigslist, a sign in your yard, looking fir bike parts, sift thru the hundreds of turds and hope to get lucky, or stumble on a set nobody knows what it is (better be quick and click buy it now if it's on eBay.) or, just realize they aren't worth the money and forget about it.

I think you right on.. there I would like to have a set but for the crazy money they are asking ill pass.

No eBay APP ID and/or Cert ID defined in Kunena configuration

strum wrote: heres anewly listed set . I emailed the seller and told him these are NOT 29mmSMs

LMBO!!! My point exactly. "OEM?" WOW ur kidding me right? It might explain this seller's ill-knowledge seeing as his name is "BMW-parts"! ROFL! I agree, some sellers just list things and hope to luck on to bids. Buyer beware ESPECIALLY on ebay...................................Mike

Zoom-zoom!!!