Mikuni or Keihin for KZ900... Your thoughts?

Hey all,

While researching WTF I'm going to do with this bike, I came across two members that had different opinions regarding this subject matter...

I realize we all have different motors, (street vs. track vs. drag)riding styles, power requirements and such but I'd like to hear from others on what they have and what issues they have had with either of these two carbs. Basically pros and cons if known.... i.e. sync & adjustments.

My bike: 1015cc kit, unsure of CAM yet but .365 or .410.
Edited: Stock OEM 26mm carbs... :X

Probably should just ask wired George but what is the true difference between Flat Side and Round Side carbs?

Either of these two direct bolt on or is modifications required. And yes, I do realize a new push/pull throttle assembly is required as well as manifolds and filters.

Thanks and look forward to hearing from you guys,

Old Man Rock

Do you have any carbs now?

The only thing the new big carbs will give a stock?
motor is more top end....... My opinion
Try to find a set of stock 28s.. 29 smoothbore
are the best. Also best for 900-1050 motors.
Not cheep but neither are new keihin/mikuni
If I had to choose the mikuni are ALWAYS on top.

Ether set are easy bolt up, just change to correct size
intake boot. I would recommend that you mach the
head to the boot. (inside diameter) You get a little better air flow.

ILL bet you gat a bunch more opinions on this one

XENU

You can ask me but that doesn't mean I know the answer bwhahahaha - the RS34s are expensive and the CR31s are even more expensive. I haven't heard any one ever say anything good about the CR smoothbores. No personal experience. The RS34s would seem to be a bit on the BIG side... slow airspeed will make off idle lags pretty much a certainty I would think. There are guys running those things on this board and dragbike.com and I would ask them although you do have to take owner input with a grain of salt. Somebody pays $600-800 for a set of those things and they are going to be loathe to admit the things don't work just peachy perfect on the street because that would make them sound like... well non-smart.

OMR- Your engine is basically a slightly hotted up stocker. I wouldn't put all that money into fancy racing carbs, if it were me. You won't see a corresponding improvement. Get some 28s with no accelerator pump or Mik 29s as has been suggested and that will be about all the gas your bike needs. Heck, if you tune the 26s right, they will have a lot more mid-range pop than the larger carbs. They make more power in the mid-range. Once you get over a certain size, the mid-range suffers and the powerband is shifted up towards the top of the rpm range. Makes the bike harder to ride and that isn't where most ride all the time anyway.

Again, as I said, when you ask opinions about real expensive aftermarket stuff, hardly anyone is gonna say... I SPENT $800 AND THE BIKE HAS NOT MID-RANGE AND WON'T IDLE.

wiredgeorge wrote:

You can ask me but that doesn't mean I know the answer bwhahahaha - the RS34s are expensive and the CR31s are even more expensive. I haven't heard any one ever say anything good about the CR smoothbores. No personal experience. The RS34s would seem to be a bit on the BIG side... slow airspeed will make off idle lags pretty much a certainty I would think. There are guys running those things on this board and dragbike.com and I would ask them although you do have to take owner input with a grain of salt. Somebody pays $600-800 for a set of those things and they are going to be loathe to admit the things don't work just peachy perfect on the street because that would make them sound like... well non-smart.

OMR- Your engine is basically a slightly hotted up stocker. I wouldn't put all that money into fancy racing carbs, if it were me. You won't see a corresponding improvement. Get some 28s with no accelerator pump or Mik 29s as has been suggested and that will be about all the gas your bike needs. Heck, if you tune the 26s right, they will have a lot more mid-range pop than the larger carbs. They make more power in the mid-range. Once you get over a certain size, the mid-range suffers and the powerband is shifted up towards the top of the rpm range. Makes the bike harder to ride and that isn't where most ride all the time anyway.

Again, as I said, when you ask opinions about real expensive aftermarket stuff, hardly anyone is gonna say... I SPENT $800 AND THE BIKE HAS NOT MID-RANGE AND WON'T IDLE.

your stock is rising wired one!

I didnt spend but half that much for 33 smoothbores and traded them even for 29's. Never could get the 33's streetable but they ran good wide open. Much happier with the 29's. On a stocker Id just run the 26's myself

i run 34mik flats on a 900 with lots of port/polish work,decent drop in cams,my bike does idle very well pulls very strong thrue all RPM's im more than very happy with these carbs and their performance, i think i paid 500 brand new its been about two yrs might be more$$.