I bought a 250r motor built by FTZ Racing and it has a Motoplat stator with the internal flywheel. The stator has 2 wires coming out of it; a blue and a black wire. They both have clear insulators on the connectors. I know Motoplat had two different stators (recognized by the color of the insulators), one utilized a diode and the other one did not. Trying to find out what kind of coil I need to start looking for.

 

Since no one else has come on here, I'll tell you what I know, which may be no help.

Years ago I thought it would be a good idea to add a battery to my 250R. I was tired of the light going out as I skidded around a corner with the back break locked up. The engine would restart as I let off the break and the light would come back on. Anyway I remember having to put on a full wave rectifier (diode x 4) because the stock electrical system was AC, that is the main 12volt source to the lights. Alternators are AC and since there was no stock battery to charge I guess Honda was good with this setup. I always assumed that the ignition circuit was rectified somewhere else. My point being, that the stock system should work regardless on either AC or DC - DC will pass through a rectifier just fine - AC needs the rectifier to make DC which is used on most ignition coils.

 

This motoplat system is similar to the systems used on old Husqvarna dirt bikes. There is no CDI box (at least I am told by the previous owner of this engine). I would think with this system, there would have to be a diode in either the stator or the ignition coil itself. I ohmed the stator last night (set meter on diode) and get the same reading on both wires. I wonder if a stock 250r coil would have this diode? If I need it at all?

 

Well you are going to need DC one way or another for the coil.

If you are not going to use the CDI has the pulse generator been replaced with a set of points?

I see on my 250x there is a diode external to the CDI box. Since the diag does not show inside the CDI box I am not sure of it's function, but I'll bet it is DC for the spark.

There is also an external voltage regulator. You will need to regulate the voltage output of the alt or you will cook your coil.

 

I can see where it would have to be regulated. Thats the other part of my dilemma. All the diagrams i can find for this system show the blue wire and black wire plugging straight into the coil from the stator. I wonder if there is a regulator built into the stator or coil itself..... Motoplat has been out of business since 1993 and I've only found limited information on there systems. I havent even found an actual book diagram of it. Only handwritten. Thinking I may get rid of the outdated Motoplat altogether and order something else. Any ideas which ignition I need? I'll be running alcohol, 39.5mm carb, stroked 4mm, and an FTZ pipe. I was looking at the FTZ ignition, but that system is $475. I already have a sh%tload of money in this thing and havent even started fabricating the frame yet!

 

I found an after market system for a 1988 CR125. Will this possibly fit my 1988 TRX250R case and crankshaft? It's an internal flywheel system. PLV analog (whatever that stands for?). Part #CW70100