starter motor arching out

[good ol stoners]

My car is an ae101 levin which i did a 20v manual conversion from a 4afe auto.
Took my car away to auckland from wellington in the weekend got up there and just cruiseing round with the drags gone to three or four different places, then at east tamaki when to start the car it just died draining all power out of the battery and smoke coming out of the engine (like a short). Pushed the car to the service station try jumper leads car was shorting out when the key was off.
We realised the earth was hot so by chance though it was the starter motor and broke the power cable for the starter motor off the battery terminal and the car went fine after that.
Other than pushing it every time i needed to start it.
Had a mate take the starter motor to work and he cleaned it down for me and tested it and its working perfectly.
Does anyone know what would cause it to arch out? I've checked all the grounds. Or could some one please tell me the starter motor circuits so i can check all components of it please.

Any help would be great
My shoulders are sorta getting sore from pushing the car.

[crnkin]

this seems like a dum question, but its happened alot...

have you followed the appropriate wires from the starter motor to check theyre not actually burnt to the exhaust manifold/system?

its happened to me twice, took ages to find, and has happened to many cars before, its the most likely cause!

[good ol stoners]

Have checked. Starter motor is on the back of the engine and the wires only extend a few inches out of the loom. So its hard to melt to exhaust, but no damage to any of the wires.