Heat soak?

[David Fallon]

Hi;

I'm hoping someone's experience will save me some trouble.  The last  
three times I have ridden my 80 KZ750 it has gone down to two  
cylinders when restarted.  I have ridden for about an hour getting to  
my destination.  About an hour later I come back to the bike to ride  
home.  When I start the engine, it runs on only two cylinders; the  
#2-3 combo.  The #1-4 are dead with no spark as they share the  
ignition.  I have enough power with two cylinders so I head for home.   
After about 3 miles, the dead ignition kicks in with no further  
trouble.  It runs great all the way home.

I cleaned the wire connectors, tightened the connectors, ohmed out the  
sensors and box which all test good per the manual.  A few months ago,  
I installed new Dyna coils.  When I installed the coils, I worked all  
the 12V connections to the coils to reduce the voltage loss in that  
long convoluted wiring mess.

I'm wondering, is this the classic heat soak behavior of the solid  
state device?  Is swapping on other components the only way to check?

Thanks  for any advice or pointers.

The KZ is too much fun for an old guy like me!

David Fallon