Merc50hp 500 Thunderbolt

[ecslayer]

I have a 50hp Merc that needs a powerhead. The motor is a 1978. Can anyone tell me if the powerhead from a 1974 will work on it? Thanks in advance for any help. ecslayer.

 

[steelespike]

Re: Merc50hp 500 Thunderbolt

If no one can help here try Johns Old Mercury Web Site.

 

[Faztbullet]

Re: Merc50hp 500 Thunderbolt

They will not interchange. The 74 has the thunderbolt distributer and the 78has adi ignition. Even the switch wiring is different.