C15 2 Stroke only firing on one. Wiring (diagram) anyone?

[jonrarit]

I've picked up an old 80's/90's Yamaha C15 2 stroke which is only firing on one cylinder.

Swapping the wire to the coils moves the problem to the other coil confirming both coils ok however if only one coil is connected at a time there is no spark to either...ie both coils need to be connected albeit only one fires.

From the pick up there is an orange, grey and black wire. The black is the earth. Both grey and orange have twin female bullet connectors (why twin ends by the way?)

The emergency stop has a single white wire with a male bullet connector but no matching female anywhere (other than on of the two "spare" pick up ones?

Does anyone have a wiring diagram or idea why it is only firing on one? Under the flywheel is there two pick ups? ie one for each cylinder, maybe one has failed? Is this common/likely. Also where does the single white stop switch wire go?

All suggestions welcome

thanks in advance

JR

[boscoe99]

What is the engine ID number. Should be on a data plate affixed to the left hand clamp bracket.

[jonrarit]

Wahay, all sorted.

Pulled it apart to find good old school points and condenser. One set had oxidised up. Quick clean up and big juicy sparks all round. Brought back so many memories of youthful tinkering with x flows.

There's a lot to be said for simple mechanical engineering

Jr

[99yam40]

makes me wonder how far back you need to go to find a C15 with points and condenser.
Probably farther than the 80s and 90s, but not sure

[boscoe99]

A C15 was never offered here in the states. I can't think of any Yam with points. I know that my 1981 Merc 25 two stroke did not have them. Thank God.