TOPIC:

1979 KZ1300 A-2

So I’m working through sorting a idle speed issue, in that, if left to idle the bike switches off after a few seconds, need to keep it at 1200 or so to keep it going (assuming my rev counter is reading right) so I’ve taken the carbs off, cleaned them in an ultrasonic, replaced o rings where needed. Otherwise just ultrasonic plus carb cleaner on everything. Put them back on, and now seems to be running on only outer 4 cylinders, at least, at idle the exhaust pipes are getting up to around 120C, and inside two only around 60C. Could the mixture/balance be so far out to cause this? Or something else going on? My next actions are, check there is at least some fuel on the bottom, don’t have a level check yet. But then take them off, clean centre again at least, then do a static balance, to the paper dragging evenly on them all, then try 3 ish turns on mixture as I set them as they were which was just over 2 turns before. See how it turns there. After that use a colour tune hopefully to get the mixture right, maybe just adjust the balance and mixture manually for max idle? I can get a hold of a vacuum balancer off my neighbour but not seen or tried it yet. Anyone got any thoughts/recommendations on setting my carbs up right? scotch, can you save me?

Scotch posted the definitive guide to rebuilding these carbs some time ago:

www.kz1300.com/index.php/forum/carburato...rb-rebuild-pt-1#5423

Since then, there have been many follow up posts, including coverage of the procedure for setting up the throttle and enrichment linkages, synchronising - both before refitting the carbs and then with the engine running.  There must be several hours worth of reading on the subject of carbs on this site. A recurring theme in many posts is the paramount importance of cleaning deposits from the fuel galleries, for which purpose Scotch designed a tool. 
Best wishes for a successful outcome.

Don't blame the carburetors so quickly.  The center two cylinders (3 & 4) get spark from one ignition coil and one pickup coil. 
My suggestion is as follows:
1. Test compression on all 6 cylinders.  Maybe 3 & 4 have low or zero compression.
2. Check for spark at spark plugs for 3 & 4.  If no spark -
3. Test the ignition coil for cylinders 3 & 4.
4. Test the pickup coil for cylinders 3 & 4.
Good luck

+1 especially regarding the ignition coil. Kawasaki parked the coils up high in the frame behind the steering head and as such, there's little to no cooling for those coils and they are right above the engine absorbing heat.

Not the coils at least, got spark on 3 and 4, though 3 was quite fouled, got a compression tester and colour tune on the way to check compression and mixture, hopefully with those I can get it running right. I don't think it's actually fully misfiring, just maybe not running right, as it wouldn't start at all with plug 4 out, though did with 3 out, so maybe just not running on 3. short video of it running best as it can below. Thanks for tips all.

I've been through scotch's posts and first few pages of that thread, but it is a lot, will check for more.

YT KZ1300 running

Got my compressions, all seem fine, cold, WOT:
1: 112
2: 112
3: 104
4:110
5: 90?
6: 100?

5 and 6 the tester was leaking out at the spark plug, so not entirely accurate, but with 5 leaking more than 6, think they are all fine for 30k miles

Also had the colourtune on, think it's only actually not running on 3 and suspect of the air mixture screw o rings, so going to swap those out today, it's certainly sounding a lot better, out today on it and at more open throttle everything comes alive and gives a nice howl.