I'm rebuilding/reassembling a Rotax 503 for a friend. Most of the information regarding the build has been found from parts diagrams, owner's manuals, and maintenance manuals.

However, I see a tricky spot coming up soon. I have the main engine assembly complete, and will be reinstalling the top shroud and the belt driven cooling fan shortly (as soon as the top shroud is done de-greasing). The problem I foresee is that I do not know which spark plug wire attaches to which coil.

The coils are mounted vertically on the cooling fan's metal housing assembly. Fortunately, the two sets of wires that attach to the coils has one of them labeled "lower"...so the other set of wires is easy to figure out.

After I figure out which spark plug wire goes to which coil, and I reattach the coil wires, I still have four wires coming from the block with no happy place.

The wires are:
- a yellow wire
- a yellow w/ black solid line
- a green black striped line
- a green w/ black solid line

So... Can anyone help me with which coil goes to which cylinder? And does anyone have a good wiring diagram for the engine and/or a paraglide (?) ultralight?
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