TOPIC:

Thanks Scotch, good advice as always.  I fitted 2.4mm ID jets which were really effective in getting the choke circuit to work but probably too restrictive for the rest of the system to cope with once started.  I agree that modifying the fast idle cam is a no-return option which I would steer clear of.
I did think about drilling my jets out in incremental steps to see if I could solve the cold start stability issue, but with no specific data or experience from other owners to work with, decided that the hassle of removing the carbs on multiple occasions, when the rest of the system was working so well, was not worth the effort, especially as my only real issue was the first start after the winter layup.
When I had issues with my starter motor, I swopped mine out temporarily with one fitted to a Z900 that was undergoing a rebuild as the starter is exactly the same.  I then bought a re-conditioned unit to replace mine but I still have the old starter motor with the shorted out stator windings in my parts box.
I think maybe Kawasaki have under specified the starter motor in the first place - fitting the Z1300 with the same unit as the Z900 with 400cc more capacity means it is almost certainly underpowered.

Thanks Kawboy. That all makes sense.

For those interested, I tested it yesterday in a number of ways that used to cause issues starting. Cold, hot, multiple starts in a row, etc. It started every time with minimal effort. So far, I can't say enough about switching to a Rick's starter. They are very pricey at around $230.00 US, but as others have said, well worth it.

Short video of a Yamaha FJR 1300 starter motor drawing 170 amps, unloaded.


...and yep, a Rick's starter has the connection at the ' wrong end'. 

..and I didn't follow up to ask Rick's why. Bad on me.

 

If you look at my profile picture you can see that my Kz1300 has a Vetter Terraplane sidecar attached. I decided to remove it so that I could get to the carbs and coils a little easier. Anyway, it was too hot in my garage (already close to 90F at 10:00am) by the time I got the sidecar detached, so I decided to take just take the KZ for another cruise just to cool me off and see if the sidecar drag was effecting the problem.

I again rev'd it up thru the gears and held it steady at 4k for a couple of miles. No power issues. As I pulled up to a stop sign, it seemed to be be loosing power. I again rev'd it up a couple of times which seemed to clear the issue. I then road around at various speeds averaging 3 to 4.5k RPM holding steady for a while then accelerating and decelerating, then back to a steady speed. I probably rode 8-10 miles with no issues.

One thing to note, I have a fan switch installed and had the fan from the start to keep the temp down. I turned the fan off the last couple of miles and let the bike heat up to close to max temp and still no issues.  Ugg. More to follow once this heat wave settles down some.