Motoplat question..

[Charles Gresham]

Whats the diffrence between the red and black spark plug wire on Motoplat coils, if any?

1974 Penton 250 Hare Scrambler
1973 Honda CL 100
1978 Suzuki RM 125
1983 Honda XL 185
1993 Yamaha RT 180

[firstturn]

Charles,
  I do not know if you have used the "Search" button at the top of the page.  This is what I found under black wire.  You could search coil. etc and get enough information to keep you busy for several hours.  I hope this helps.

The Motoplat coil thing is sort of complex, but there are some rules that can be used. First off, if the coil has a red spark plug wire, it can be used on any Motoplat magneto. There are two different "shapes" of coils with red wires, but both are interchangeable.

The two differ in size a little bit, as well as having their connecting spades in reversed order. The earlier version, has the large terminal between the small terminal and the spark plug wire. The later version, has these positions reversed.

In the early 1980's, Motoplat decided to reverse the polarity of the system, and at that point, they went back to the black spark plug wire. They left the rest of the coil the same, but because the spark plug wire was again black, like the coils prior to 1974, this has caused some confusion. If you have a coil with a black wire, but the small terminal is between the spark plug wire and the large terminal, it will also work with any Motoplat magneto.

The black wired coil that will not work, are the ones with the large terminal between the spark plug wire and the small terminal.

I hope this has been of some help. If you need more information or clarification, please give me a call at 440-988-4474.

Dane



Edited by - dandk on 06/08/2003 09:55:36 AM


Ron Carbaugh

[Charles Gresham]

Thanks Ron!

1974 Penton 250 Hare Scrambler
1973 Honda CL 100
1978 Suzuki RM 125
1983 Honda XL 185
1993 Yamaha RT 180

[TGTech]

Charles,

In January of 1974, Motoplat moved the diode from the stator to the coil/CDI and that when the "black" coil/CDI wire went from to the red wire. In the early 1980's, they changed the electronics again, and that when they went back to the black coil/CDI wire.

You can use the red wire and the late black wire coil/CDI, for any version of the Motoplats. But use have to use the red or late black coil/CDI on the versions of the 1974 and later.

Dane

[Charles Gresham]

Thanks Dane !

1974 Penton 250 Hare Scrambler
1974 Yamaha MX100
1973 Honda CL 100
1978 Suzuki RM 125
1983 Honda XL 185
1993 Yamaha RT 180