88/89 MC18 with PGM II, MC24 engine. Had it running on the stand for the first time a while ago but the RC Valve circuit was fried. Sent the PGM II to 2TRacelabs for rebuild of the RC Valve circuit and total refurbishment. Nick says he tested it and it was working perfectly. Was unable to start the bike yesterday. There was spark at the front cylinder but not the rear. Today i can get intermittent, or more accurately, occasional spark at the rear cylinder. I switched the front and rear coils and same result. The coil hooked to the front LT wires gives spark as intended, the one hooked to the rear HT wires only sparks occasionally. All connectors and terminals were cleaned and look in good shape. The black wire going to the rear coil is quite a bit shorter than the green and white wire suggesting a possible issue there? Battery fully charged.

HOping to hear this is a known problem with known solution, before working my way back through the whole wiring harness. Any suggestions welcome.