Hi,

swapping my 92 engine to 05 one. Question is about the wires from the gearbox. 92 engine has  a single wire and 05 model has 3 wires coming out of the gearbox. keeping the 92 wiring loom. What are these extra wires and how to connect them to my old w/loom?


cheers,
Lauri

Hmm,

A look at the wiring diagram for the '92 vs the '05 shows the difference being the neutral selector having a N/O contact reference to ground. Is the single wire a blue one on your '92 engine?

The '05 wiring diagram shows some sort of Voodoo 3 wire magic box, but I would assume your '05 has a blue, red with black dot, and green with black dot wiring colors? in the '05 model the blue wire goes into a small diode block that simply provides a convenient means to ground the neutral lamp, and feeds into the side stand / cutout circuit.

*** at your own risk *** - or if someone else has better knowledge

I would surmise that the blue wire is still the neutral gear indication - and that the other two wires would not be required for a '92 to run correctly.  The other two wires appear to provide some sort of interlock / reference of neutral back into the ignition control unit in the '05 model.  I would isolate the ends of these to not swing in the breeze and see what happens..

Oh great sages of GSTwins.. I beseech thee to provide any further insights... 

Thank You, will give it a go.

Lauri

Just checked the diagram. One is for the ordinary diode clutch /neutral cut to the starter and the others to the ECU ( still called an igniter) to cut the spark by the looks. By 05 the sparks are completely controlled by the ecu , so the old simple coil earth/power cut no longer works.

I would suggest a quick check on the '05 engine between the blue wire and ground - see if it replicates the signal you get from the '95 engine neutral position. Just use an ohm meter on low ohms and see if you get a clean signal when you shift the engine into neutral.

I don't think this would work the other way around ('92 into an '05 frame) as Gregjet has indicated you have the extra 2 wires on the '05 harness and you would need to mess with a bunch more wiring.

Let us know how you get on.

At the end connected the blue only as advised and isolated the other two from touching anything. Neutral light comes on in neutral  and goes off as changing into gear. All good.  At the same time wired also electric clocks in and got everything working.

Interestingly after doing the engine swap the one thing i noticed is that 05 engine has some funny vibration at 5000 rpm. Defo didn't have that on the old one. Will go over all the nuts and bolts to see if anything is a bit loose, but otherwise its like riding a different bike now. So much more pull and no more funny noises.  So all in all well worth swap. Now got a dilemma what to do with an old engine? it has done 76 000 miles, keep as spares or flog it?

Cheers,
Lauri

You could always look out for a cheap go-kart frame..

(great to hear the transplant was a success btw)