I want to put in a safety laynard on my 240 sport..It has a 96 502 in it..what wires do I need to connect it between?

I put mine in the ignition wire path after the key. In theory, you should be able to remove your ignition wire from the key, put it on one side of the kill switch, then run a jumper from the other side of the kill switch to they key where the ignition wire used to go.

Keyswitch > kill switch > ignition

Where can you buy a kill switch?

what color wire did you interupt it on c-deezy?

Sierra International MP40970-1 Marine Emergency Cut Off Switch
Amazon.com

Purple. You should have Red, yellow, purple at your key.

Red - +12V from harness
Yellow - Starter
Purple - Ignition