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Ahhh now it's clear, thanks I often wondered, now I know, cheers

Hi Pete,
I guess I should have gone a bit further on my last post. The reason we sync the carbs last is because so many other things affect the way an engine breathes. Including: Compression, valve adjustment and valve timing. Perhaps even ignition timing, although I'm not certain on that one. Once you're sure these are within spec you can sync the carbs.

Imagine an engine that runs but has poorly adjusted valves. It's possible to sync even these carbs. However, if you were to adjust the valves, last, so that they worked more efficiently the carb sync would now be way off.

While were on syncing carbs: I've always thought that if you can get a bike to idle smoothly the carbs are close enough.

Any body out there who can shed more light on the benefits of carb syncing?

Bill

Ok on that kind of gauge 18 is good mine say a 1/3 of the way up so your good at 18. I just redone my KZ1300 and been in the carbs twice now. Ok I explain as best I can to lines of thought. When you open the ex up it means the bike should breath better thats is why they say jet it up. But most people also go with pods and not the air box meaning more air in carbs so more jetting. Still with me. Now what you have done is only one part of that so you should not have to jet more than one step up if at all. here is what I did on set up. I went 3 1/2 turns on mixture screws and fond I had a miss at idle and just off idle. So I set all 6 of the screws at 3 1/4 turns and miss is gone and smooth all the way up. now the fact that your running a header or 6 into 1 I would try backing the 6 mixture screw out a bit to richen it up a bit . And do this only one notch at a time . lift the needle vavle up one notch and see what happens. here is why I say this. when you study these carbs you learn that idle to 1/4 throtle is controls by mixture screw and main jets. From 1/4 to 3/4 throtle is then controled by main jets and needle seats valves. That is how all motorcycle carbs works. your better to be a bit rich and I mean a very little bit. Being lean will cause you to pop and back fire. to rich will also do the same. So I hope that helps you.

oh yeah alway use your center carb to set your gauges up first. and alway use your center carb as the guide fro the out side carbs because getting to the mixture screw are easyer on the out side carbs.

Ok, I'm pretty sure I understand now, after doing the valve stem seals last weekend, I also did all the shims, new valves a little while ago, so they are all within specs now (my fault when putting them back in I mixed the whole lot up, so the exhaust shims ended up in the inlet, won't go into how dumb dumb me did it, ok?), so this weekend i'm doing the balance and the mixture again as she was burning a bit of oil in number 1 cylinder because of an old split stem seal, at present she is running good, although number 1 is burning a bit hot, too rich probably, i'll do the balance using the gauges, always balance using the center one as the set point, then i'll do the idle using the colortune plug, i'll let you know who it goes, fingers crossed I won't stuff it up, cheers

Yep balance was out a tad after the shim fix, also the idle mixture, balance set to center carbie, still around the 18 mark, colortune plug showed a couple of cylinders running a little rich, and a couple too lean, not firing each stroke, so "tweeked" the screws, all showing a nice blue flame and a flame at each stroke, purring like a kitten, will take her for a decent run tomorrow, cheers Pete.