Stator help trx300 wiring harness and 250sx motor

[cybrman]

Ok so I had a trx300 motor in my 250sx, complete with the harness from the trx (89 model btw).
The 300 motor smoked real bad and I had a 250 motor I just rebuilt and so I decided to put the 250 motor back in the 250sx.
My problems began when I notice the stator has 3 yellow wires that go to the rectifier and has another 3 wire connection along with an extra 4th wire. Well the 300 only had 3 yellow going to the rectifier and 3 wires for the other connection.
I managed to hook the 4>3 up and had spark woohoo (or so I thought). Started her up and she barely runs and will not accelerate. Halfway into the throttle she just dies.
So it sounds like something is wrong with the spark advance (is my guess at this point).

The question(s)
1. Not having found a 89 trx 300 manual I have no way to accurately figure out if this can be wired up and work. I'm hopeing someone can tell me if this is possible.

or

2. Another alternative that I am in the process of investigating is just swapping the stator and flywheel from the trx engine into the 250sx engine. It looks like it should work but I haven't finished removing the flywheel off the 300 engine. Anyone have any experience with this that could tell me for sure this is the better idea?

Any help is appreciated
Thanks
Rick

[TeamGeek6]

flywheel mass is critical, its part of the crankshaft mass.

if you can post wiring diagrams from the cycle that donated the stator and pulse generator, AND the cycle that donated the ignition and wiring, Ill give it a stab.

Wiring diagrams are on the 3WW home page.

PM me when you get them posted in case i lose the thread.

[cybrman]

TG
Thanks for the response....I have been unable to locate a manual/schematic for the trx300 as I indicated initially.

[cybrman]

At work, busy day, haven't been able to follow up as I'd like...

TG from your comments I am assuming the flywheels must be of the same weight? The trx300 flywheel is smaller in diameter than the 250sx. It seems more "beefy" though and my guess is that they will be close. Once I get both removed I will compare them. Do they need to be exact? or how close can they be?

Thanks
Rick

[cybrman]

In case anyone is wondering....

You cannot swap an 85 250sx flywheel with an 89 trx 300 flywheel
but you can swap the pulse generator !! Woohoo..

Why do I always do things the hard way...
Pulled both flywheels off to see if I could swap em so I could swap stators (diff diameter).
I also wanted the covers swapped because then I could use the starter reduction gears from the 300 which are thicker and would be more durable.
But really I could've avoided all the fun by simply swapping the pulse generator and modifying 1 wire.
(not to mention pulling the head cover 3 times to "triple check" the timing when I knew damn well it was right.)
Ahh well its all part of the experience I guess.....at least now I know.

[aldochina]

so is the problem fixed?

[cybrman]

Guess I got so caught up in the story I forgot the happy ending lol
You bet! she fired right up and purrs like a kitten!!
Trying to get ready for a ride this weekend...