Smokin gsx!

[Rhubarb]

Unfortunatley, despite what the thread title may suggest its not the rear tyre or the rider thats smoking - it's the wiring!

My 80's GSX has a black wire with a white tracer that is getting so hot it is melting the plastic wire coating.

It only smokes when I use the starter so obviously it is linked to that.

My battery tester says the battery is 75% charged but the starter winds over like the battery is flat. When I use my jump starter it still winds over really slow. (Instead of all the power going to the stater it may be shorting out - I'm not sure, just a guess)

Being a black wire I assume it is an earth wire?

I haven't ridden the bike for a couple of weeks. The last time I rode it was about a 2 hour ride home from an overnight stay. Everything went well, bike performed great - no problems. I parked it in the garage and was looking forward to the next sunny winters ride.

I have put a new rear shock absorber on it since the last ride but there is nothing remotely electrically related to the shockie change.

Does anyone have any ideas how I can find/trace the fault?

Thank you for your help.

[JMemonic]

Black with white is normally earth, seems odd.

[Sam I Am]

Did you take off the seat when you did the shock ?
if so look for crushed/ trapped wires under there.

[mossy1200]

voltage = current times resistance
if your saying you voltage is low then the formula means the current has to increase because the starter winding resistance is constant.

Increased current = increase in heat.
cranking with low voltage = increased heat for longer period of time therefore problems compounded.
Or the current is traveling on the incorrect cable.the starter ground cable is large(thick).What size is this cable and does it go dirrectly to chasis from starter or is a small cable on the soliniod .

[Jantar]

Your starter motor has a broken earth return and its trying to use the solenoid earth as its main return. Unfortunately, as you are finding out, a wire designed for 10 Amps gets very hot when you you try and push 110 Amps through it.

[Rhubarb]

Did you take off the seat when you did the shock ?
if so look for crushed/ trapped wires under there.

I did but I haven't put it back on yet. There may be some pinched wires elsewhere though. I'll search around to see what I can unearth (bad pun - sorry)

Thank you

[Rhubarb]

What size is this cable and does it go dirrectly to chasis from starter or is a small cable on the soliniod .

It is a small black cable with a white tracer, it is not a heavy earth like the one coming from the battery.

I'll go through the wiring diagram in the workshop manual to trace it's starting and finishing positions.

[Rhubarb]

Your starter motor has a broken earth return and its trying to use the solenoid earth as its main return. Unfortunately, as you are finding out, a wire designed for 10 Amps gets very hot when you you try and push 110 Amps through it.

Thank you. I'll start at the starter (a good place to start!) and trace it back from there.

Thank you.