Hi All,
Im trying to eliminate a electrical problem I have with my Blue 750. I am thinking of trying a new harness, can anyone tell me if a 906 harness is compatible?

Thanks

Definitely maybe..... It will have more stuff for the water cooling tho.

What issues are you having with the original??

They do show up on evilbay once in a while.

Hi Jon,
Im a bit crap at electrics, I have the nice guy's at Rosso Corse in East London looking at my bike.
We just rebuild the motor and it was running fine for it's MOT and then it stopped dead.

They have tested all the major components, (alternator, ignition, regulating unit etc) and have checked/replace the all the connectors. We are at a bit of a loss and were going to try a hew harness. It has fresh MOT and tax disk ready to go! but it wont go! which is frustrating...

I noticed there was a reasonably priced one on the Bay and thought Id get it if it swapped over ok.

Jeff

Im no expert but I thought that the 750 and the 906 have different ignition systems and as such a 906 harness may bring more problems than it solves

Check the FAQ, but read this first:

It may be for hard starters, but it can be the cure for a world of other 'unseen' electrical problems.

Thanks everyone,
Yes I got the wiring upgrade and passed that on to him. I'll hold off on the harness and see where we get to.

Jeff

A new/different model harness is drastic, try a wiring diagram and continuity tester. If the motor has stopped then its only a few wires that need to be checked. A direct short to earth would cut the sparks but there would also be plenty of smoke so scratch that! That leaves ignition unit to coils, ignition timing pick-up and voltage to the ignition unit + various earth connections. The ignition unit might have packed up but its usually the 906 Digiplex that does that unless a 'battery booster' has been used which can fry the ignition unit due to the higher voltage it applies. A connector block might have corroded with subsequent circuit break so I think you should look at these possibilities before attempting such a swap over.

As a heads up theres a fella Liverpool way who has been trying to flog an old and a new 906 harness on fleabay recently £49 and around £80 with no takers.

Do not buy a 906 wiring harness and do not do the wiring mod.

The 906 has a Marelli Digiplex ignition, different coils, is water cooled hence has different sensors. The wiring may fit for the lights, instrument panel, sidestand switch, horn etc but not for the important parts.
As JW stated the wiring is simple. Get a circuit diagram and a voltmeter and go through the wiring step by step.
If it`s totally dead check the 12V from battery to starter relay. If there are 12V press the starter button and measure the voltage at the thin red wire on the starter relay. If there`s 0V flick the ON/OFF switch while measuring and pressing the starter button. If there`s still 0V check the route to the ignition switch and the start switch. If there is 12V measure the voltage at the connector to the starter. If there is 12V check the starter motor, if there`s not change the starter relay. If all this is fine the bike should at least crank. If it does but not fire up check the voltage at the coils. If that is ok I`ll point towards the Digiplex ignition unit. So step by step check all.

Don`t do any modifications to the wiring as long as you didn`t find the issue!
It`ll also help to explain to us what the bike exactly does or doesn`t. What do you mean by dead. Totally, do the lights come on, does it crank ... ?!

G.

If the bike was totally "dead", I bet on a starter relay issue.
Check at the relay's connections, they go easily rusty.
Good luck

Hi all,
Thanks very much fro the help, by "dead" I mean no spark. All lights and starter motor turns the bike over without spark. I installed a reconditioned starter motor in the bike already. I am going to spend the day with a friend working through the system and see where we get to. I'll let you know how I get on.

Cheers!
Jeff

(Cant wait to get some use out of that fresh tax disk).

another thing to check then would be the RH switch assy inc the harness and particularly the plug .Power to the magic box goes thru this via the kill switch