Speedfight 2 100cc engine swop

Hi ok i have a 04 100cc speed fight i have taken the 04 engine out and replaced it with one from an earlier model , it starts and now runs backwards, i have only managed to get it to run forward once. So i have done the check for bad earth and replaced the ecu. as suggested in other posts i had found on here .
I have noticed that the replacement engine has a extra wire from the stator that the original dose not have. this wire is Black with a red tracer.
Ok so heres the question can any one tell me what is for, ie is it to earth the stator out.
I was tempted to just earth it and see what happened but my wallet would not let me as it kept saying i can't afford a other new CDI in case it blew up!!
So please any help or links to wiring diagrams would really help
Cheers Mark

 

what do you meen runs backwards?

can you use your 2004 stator plate with the other engine?

 

I think earth is usually a green wire on speedfights. Just switch the stators over from your old engine.

If its running backwards it's usually a timing problem.

 

how would it run backwards? i cant get ma head round how you could even start it the starting mechanisms dont work in reverse?!!

 

From what ive read on here before, 2 strokes are quite happy to run either way.

 

yh that is true but i dont get how you could start the engine to run backwards when the kickstart and starter motor run forwards yano.

 

Hi thanks for your replys and i am going to swop the stators over today and let you all know;-)
Lance 'aka' lazy, i am also a bit mistifyed to but all i can find out is that the ingnition sparks before top dead center but way to early and it causes the pistion to kick back with enought momentum that starts the whole clyinder cycle backwards !!

 

It's actually quite simple to be honest thinking about it. I know my 50 engine kinda shoots backwards when being started.

 

ooh yeah thats a rare one iv never experianced this problem before

 

Why they do not give you a picture of the wiring for a speed fight 100cc

 

Speedfight schematics ( wire diagrams)

without imobbilizer and with immobilizer

 

Do you have a picture of a finished harness please thanks

 

sorry boo boo , only have the wire schematics

 

Ok but I'd like to see a harness if you can get me one please send it ok thanks for your time

 

This type of thing happens when using L/C runner flywheels on A/C 125 typhoon engines, people think they are the same but NO, different keyway position in the flywheel makes them run backwards!