Need of wiring diagram!!

[trihull59]

I have a Mercury thunderbolt 850 and im switching over parts from a older 850 and noticed there are differences like the coil and carbs and other things so i am looking for a wiring diagram so i can figure out how to hook up everything. Serial number is 4101442 Mercury Thunderbolt 850
Thanks in advance!

[Chris1956]

Take a look at the maxrules.com website. Most any diaghram for a motor with distributor ignition will be very close to yours.

[Chris1956]

BTW - The carbs and other non-ign parts are interchangeable.

[trihull59]

what about coils and switchbox ect?

[trihull59]

oh and my serial number is not listed on that website any other sites thanks!

[Chris1956]

If they are both battery/distributor CDI ign motors, the switchbox and coil are interchangable. The one with the serial number you gave likely has that kind of ign. What kind of ign does the other have? Can you describe it?

[trihull59]

the other motor is a 73' mercury outboard 850 thunderbolt ignition
the coil looks a lot bigger on the 73 then it does on the newer motor but the switch boxes are identical the other serial number is 349 something i cant remember it off the top of my head

[Chris1956]

Yeah, Those '73 850 had the big ugly red coil, and big ugly rectifier. The newer ones (heart shaped coil in grey metal box, and three terminal black chicklet-shaped rectifier) will work with the dist and switchbox.

[trihull59]

wait so i can or i cant use the rectifier and coil on the other motor? lol