Mercruiser and thunderbolt ignition

[jims427400]

I have a 1992 220BR w/ 5.7 alpha 1. Curious if I have electronic ignition. When did Mercury switch over from points? I am the original owner..

 

[dwna1a]

Best guess is yes. Look over at your raiser it might be mounted there. Also look at the distributer, my neighbors is mounted to the bottom edge of the cap

They do go bad and when they do its a PITA. Do what many have done here and replace the whole system. Distributer costs around $375. New ICM runs around $600.

 

[BillK2632]

Mercruiser used the Thunderbolt IV from 1982-1996 so that is likely what you have.

 

[jims427400]

Thank you both, that's what I wanted to hear. I am going to do some research and find out what options I could use if my original fails..

 

[BoilerXing]

Mercruiser used the Thunderbolt IV from 1982-1996 so that is likely what you have.

Do you know what kind of ignition was used before '82? Mine went bad ('78) tonight & decided to "spring" back to off instead of to run.
Also, can it be replaced with an auto ignition or does it have to be a marine ignition?

 

[BillK2632]

I don't know, but would guess it was not an electronic ignition system - ie points/condensor. There are a number of companies that make aftermarket replacement systems for the Thunderbolt IV system - Sierra, SBC etc. They would include the distributor, ignition module, wires etc. I've never looked into them, so I can't say which ones are good. As far as an auto system, might work, but it's not going to meet the specifications for spark arresting for a marine environment.