Yamaha 115 no spark on port cylinders

I have a 89 115 that loose spark on #2 and 4 cylinders once it warms up. After it sits for a while the spark returns for a run untill hot again. A defective pulse coil makes perfect sence but the resistance test is bang-on when tested at the time of the problem.
The manual also provides checks for 2 ignition charge (source) coils located in the stator assembly. One with low resistance and the second with high resistance (1150 ohms). Both these coils also test within spec but I have noticed the high resistance coil resistance will fluctuate a few hundred ohms when tapped with the handle of a screwdriver. I was thinking this is due to an problem in the coil windings. The problem is that there is no explanation as to how these two coils funtion in the ignition system so I don't know if they may be isolated to the two defective cylinders.
I have tested ignition coil resistance but having two coils go defective simotiniuosly and recover when cooled is highly unlikely.
I have a DVA meter but the yamaha manual only provides restance specs.
I have seen post on similar problems with 115s and was wondering if anyone has isolated the problem.

[boats.net]

Probably a bad pulsor coil, it has 2 pulsor coils 1 fires 1 & 3 the other 2 & 4 cylinder. The pulsor that fires 2 & 4 are the white/blue and white/green wires, peak voltage at 1000 rpm's should be 7 volts.

I have not done a peak voltage test but resistance readings on both pulse coils is exactly the same. In the past, pulse coil problems have always been detected in a resistance check.
From reading other post, I am going to order a CDI box and hope for the best.