TOPIC:

Regarding the synchronizing when the bike is running, I have Carbtune Pro. Of course never done in on KZ13, but doing it on a Goldwing made me almost mad! It's a straight forward procedure, but the adjustments are so sensitive I had to redo it much too many times. It's like playing a cat and mouse game trying to lock that nut without changing levels. I always wondered why wouldn't they implement a smoother and more precise system. Especially that with all this linkage a chance for a random different reading is quite great.

I haven't read yet about synchronizing, but just out of curiosity. Carbtune has four gauges. Do you do the first four and then the last four cylinders moving the vacuum tubes? I'd imagine a life long 'sixers' would have a six gauges set ups.I'm not there yet! lol

For each pair of carbs there is only one synchronizing adjustment screw, therefore, which ever vacuum plug you chose to remove from the inlet manifold to attach your vacuum gauge to, you can still only attach 3 vacuum gauges. There is a note , half way down the page #19 of the manual that states "Normally there will be little or no difference between the vacuum of each throat passage "
So attach 1 gauge to each pair of carbs .Synchronizing one carb of each pair actually does both.

I'm probably going against the grain on this one but I've never felt that synchronizing the carbs does much unless the sync is really out. On CV Carbs, synchronizing only make a difference at idle - which presumably helps with staring and cold running - and that's a good enough reason to do it - but it's not like it's going to provide any performance improvements.

I also find the synchronizing procedure a bit frustrating. On one of my Hondas, it's just not possible to synchronize one of the 4 carbs (according to the gauges) yet it runs and idles fine.

Sync'ing may be a pain but in my opinion it's critical. To believe that 1" to 2 " hg difference between the gauges won't make any difference, is not correct. It does and you should be able to hear that difference in the smoothness of the idle when all 3 gauges read the same. If your gauges are accurate, a difference of 1"hg +/- across the readings WILL be discernible. Sync'ing is no less important then the correct ignition timing and valve shim gap.. To suggest that a few degrees +/- on the timing mark doesn't make a difference is similarly false. You will never achieve the best performance by compromising. Everything must be adjusted correctly so all aspects are working in unison - NOT fighting against one another. The correct tuning of all the variables makes adjustments much easier and noticeable and can alert you to issues elsewhere. I believe the biggest problem for those who have a problem sync'ing correctly is that they don't take the time to first do a "static-sync." on the bench. Additionally; if the carb circuits aren't 100% clean you'll not know this if compromise has been the philosophy elsewhere. You'll end up like a puppy chasing it's tail ! Seems like a good idea at the time but accomplishes virtually nothing !

Bucko, all the points you made are definitely valid. The higher the RPM the less differences between the cylinders matters and is noticed. But at low RPM the engine might start 'knocking', and that definitely translates into less responsiveness and less power. With hundreds of times stopping and accelerating, changing gear, the bike will performs overall less efficiently than if all cylinders work the same. My Honda had the annoying 'knocking' and shaky take offs. After synchronization became very very smooth. I agree, synchronizing my GL was very annoying, but greatly improved how it works after basically I got lucky with not screwing up synchronization when tightening the nuts.
Another thing I'd say different forces than as per design might have cumulative bad effect on longevity of the engine, because of the introduced different structural stress patterns.
To visualize what I mean, every cylinder fires at very specific time in order to guarantee a smooth rotation of the shaft and is required to 'push it' with specific to current moment force. If one delivers less or out of balance closer to delivery of another cylinder, the shaft will have to absorb uneven forces. Like if you would ride a bicycle with one leg only, to picture an extreme example.

Anyway, I see synchronizing KZ procedure seems quite straight forward. And in my case, definitely looking forward to doing it!

The last time I synchronised any carbs was when I did those on my XS Eleven. I've never used the gauge-type set up for doing the job, opting rather for the mercury column type. I believe these give a steadier visual indication of the vacuum levels, but I'd be interested to hear if anybody else has an opinion on the merits of one type over the other.

As a foot note, after getting all four mercury columns levelled at idle, I noticed that if I opened the twistgrip merely enough to take the slack out of the cable, and increased the revs just the smallest amount, the balance would be thrown way out until returning to idle. So I would say, you might have well balanced carbs when the throttles are against the stop, but just off idle they might not be perfect, but that imbalance will become less as the revs rise over a certain point.
Shoot me down in flames if that is all cobblers!