Using later VFR electrics on earlier bikes

I know most of the users of this forum won't know much about the VFR750s from '88/'89 'cos they were not sold in the US during that period, but I'm wondering if any of you guys can help me with an electrical question. To give you a bit of background, the '87 model suffix in the UK/Europe was FH; the '88 suffix was FJ. I want to know if I can use FJ clocks on an FH bike - they're the same physical size, but the FJ had fuel and temp guages where the FH only had warning lights.

Quoting from an article in the May 2000 review of the VFR in Classic and Motorcycle Mechanics:

"The ignition system was also changed for the third year. On the first FG and FH versions the ignition was triggered from a small pick-up on the front inlet camshaft gear wheel. This often broke off, leaving the bike mysteriously without sparks. The later FJ and FK models used ignition triggered from the crankshaft."

The wiring diagrams also show wiring to the tachos comes from different places for the FH and FJ models. Both share a solid green ground wire. Both also share a black/brown wire feed from the 10A meter light connector on the fusebox.

On the H model, there is a blue/black feed from ignition coil 1 and the spark unit.

On the J model, there is a yellow/green feed straight from the spark unit.

So, knowing that the feed to the tachos is from different places, the $64million question is can the later tacho be used with on the earlier bike? If it can't, fine. If it can, how - without butcherig the wiring loom (if at all possible)?

Incidentally, bits of my project completed so far include the new wheels, front end swap and rear subframe. Most of the panels are also primed ready for painting. And yes, it would have been cheaper to buy an FJ to start with . . .

Thanks all


Neil