Is there anything special that need to be done to a Fuel Injected 502 to set the timing? I am guessing something needs to be unplugged or capped off like on a car.

If you do not have a plug with the jumper wire to plug into the data plug, then you can use a paperclip. Start the engine, then insert a bent paperclip into the terminals labeled A and B. This will put the computer in base timing mode. Now set the timing to 8 deg. You may have to raise the rpm to about 1500 to stabilize the timing. When it is set, remove the paperclip.

Where is the plug?

Comes off the computer that is mounted on your port exhaust manifold. Its a big waterproof plug thats hard to miss.

#5 in the picture
http://www.mercruiserparts.com/Show_...NESS+%28EFI%29

Found the plug but which wires get jumped together? I have about 6 wires in that plug

Oh man, I searched and found the thread I needed, but no answer? What wires do I jump to set the timing?

see post # 2 this thread

I found it:

http://www.offshoreonly.com/forums/s...d.php?t=103342

It even has a picture of the plug with pins A and B shown.

I read you can't set the timing. Only read the fault codes via flashes.