RS34-D21-K

Hello everyone, I have RS34-D21-K carburetors installed on my KZ1000A1 with less than 1000 kilometers on the new engine, which have never been calibrated. The motorcycle runs very well. I have some cheap vacuum gauges; what advice can you give me? Should I wait until it has more kilometers? Should I leave it as it is? The color on the stainless steel exhaust is even on all four outlets. I appreciate any information. Thank you.

I put the same set of carbs on my 77' KZ 1000 B2 and it runs great out of the box too. We also put a set of RS36 carbs on the 80' Suzuki GS 1100E and got the same result so we didn't touch it either.

A well calibrated vacuum manometer will confirm how precise the carb balance is.

If you want precision tuning, then good enough just isn't.

 

The RS34's are great carbs.  Synchronizing them with a vacuum gauge or manometer can be problematic as the carbs themselves do not have any type of vacuum port on them.  And, if using J-model carb boots to mount the carbs to an earlier KZ head, then those boots won't have any vacuum ports, either.  I always confirmed that the slide heights were the same using a piece of drill rod.  Not as accurate as the vacuum gauge method, for sure, but good enough for a race motor.  It at least will get you in the ballpark.

Mike

 

Dragbike_Mike wrote:

The RS34's are great carbs.  Synchronizing them with a vacuum gauge or manometer can be problematic as the carbs themselves do not have any type of vacuum port on them.  And, if using J-model carb boots to mount the carbs to an earlier KZ head, then those boots won't have any vacuum ports, either.  I always confirmed that the slide heights were the same using a piece of drill rod.  Not as accurate as the vacuum gauge method, for sure, but good enough for a race motor.  It at least will get you in the ballpark.

Mike




 

Hi Mike
But the carburetors I have include some rubber plugs. Aren't they for connecting the vacuum gauge? 
 

Hah!  Yes, those sure do look like vacuum ports!  I do stand corrected as Mikuni must have updated the design somewhere between the late 1990's and now.  I wish that I had that feature on my set of RS34's; especially when I was running them on the street.  

And, to answer your original question - synching your carbs with a good set of vacuum gauges can have a noticeable positive effect on your off idle throttle response, i.e. when pulling away from a dead stop.  If you're happy right now with how things stand, then no need to mess with carbs.  Maybe down the road if you really want to fine tune things.  Just my opinion.

Mike

Definitely!