Ok. Have you checked the plastic drive adaptor at the bottom of the cable is intact and not rounded off?

Not sure I understand about the light tacho. Either you need to get yourself to a Mexican food outlet, or you mean your headlights dim when the bike is revving between 4000 and 7000?
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball