RS250 tacho wiring

[GSVR]

I've got this tacho off a 1989 Honda RS250 and want to know what the wiring is so I can hook it up to my SV650.

Black must be earth but what colour is the signal wire? I'm picking blue but want to be sure.

Can I drive it straight off the ignition coil via a resistor or just a wire. How does Honda do it on this bike.

Thanks in advance. Had a bit of a look on the net for info but have other stuff to do than search all day.

Thanks in advance.

[svs]

there's an 89 rs250 manual here

The wiring diagram might help. Looks like green is 0V, but there's lots of other iinformation in there which might be useful

[GSVR]

Cool thanks Phil thats just what I was looking for.

Got it running. Blue is Signal , Black is +12v and Green is Ground.

Glad I got the wiring diagram or I might have fried it.