Mercury mariner 55 - a little help for a noob

Hi guys and gals.

a friend of mine has recently purchased his first boat project, a Wilson flyer, and made it seaworthy in the last 6 months.

he purchased a mariner 55 outboard and this seems to be running fine after a bit of work, but as I am tasked with the wiring I have a few questions.

the ignition has 8 wires on the back, but a volt meter shows that only 5 of them are individual and 3 have 2 wires coming from each contact.

these are the ones I have connected

2 black (1 connected)
2 brown (1 connected)
2 white (1 connected)
1 red

This will then crank the starter motor and fire up the engine correctly, however, turning it off will not cut the engine. Should the ignition cut the engine and if so how does it do it?

I have a purple, green and pink wires coming from the ignition switch that are not connected to anything.

the previous owner gas also made a mod that I do not understand, the brown wire used to come into the outboard and pass through a small round unit that has a switch in the back. It has been bypassed but for the life of me I do not understand why it us there. I can take a photo if needed, but anyone who can offer any advice will be my hero.

i am not sure this is for your exact motor but it may help..

No, I am afraid that doesn't help much as it's not the same as mine, or I don't know which wire in the outboard us the kill switch, but thanks for posting.
It does show that when off there should be continuity between 2 wires and there is not, so I guess I will investigate that.

anyone else have any ideas?

You have posted "Mercury Mariner" - is this a twin cylinder?? if so it's actually a Yamaha built Mariner (built for/marketed by Merc) and it will basically be a Yamaha model which will make a significant difference for the wiring etc..

Yes, it is 2 cylinders

I have checked the wiring and in position 1 (off) there is continuity between white and black, so white is the engine stop. Now all I need to know is what wire in the outboard i connect that to, soi guess I had better try and find the specific wiring diagrams

And that looks like it goes to black with yellow stripe. I'll go and have a look at the outboard and see if I can find that colour.

If you look at the serial plate and it says "Made in Japan" or the number starts 633-xxxxx,as Graham says you have a Yamaha Mariner.If that's the case here's the wiring colour codes http://www.maxrules.com/fixyamahawiring.html .
Pic of control box may help as you may have a Merc Mariner one instead of Yamaha Mariner