'86 VF500F - Electrical diagnosing help needed

After a long winter I was hoping to take the '86 VF500F out of the basement.

Work done whilst waiting for snow to melt:

Replace burnt out dashlights (thought this was causing a 10amp to pop - not the case)
Disconnect and remove blinkers (this now allowed dash lights and running tail light to work, which prior were not)

Problems created:

Neutral indicator no longer functions (not burnt out)
Idle at neutral = purrfect
1st or 2nd (with clutch engaged = misfiring / lagging of engine, pulsing of headlight and dashlights in time with the lag/misfire) - I hope to post video/sound evidence of this soon.

However - when we are in 1st or 2nd AND the brake is engaged enough to turn on the brake light -- normal idle again.

Cheers,

K