Changing Ignition System on 89' 5.7L GM Mercruiser

[T/A Hawk]

Has anyone changed the the igintion system from a thunderbolt IV to GM HEI and is this possible?

Chris
89' Wellcraft Eclipse 233 5.7L GM, Alpha One

 

[bomar76]

Re: Changing Ignition System on 89' 5.7L GM Mercruiser

Why on earth would you want to?
The TB IV is the most reliable, easy to diagnose, and dependable marine ignition system on the market.

There would be NO benefit of going to an HEI setup.

 

[Don S]

Re: Changing Ignition System on 89' 5.7L GM Mercruiser

If you are talking about an automotive HEI system because it's cheaper, forget it. It's not spark protected, and doesn't have the proper advance for a marine engine.

 

[T/A Hawk]

Re: Changing Ignition System on 89' 5.7L GM Mercruiser

That's exactly what I was thinking. Thanks, I guess I'll order parts for my Thunderbolt.

 

[Don S]

Re: Changing Ignition System on 89' 5.7L GM Mercruiser

What exactly is wrong?

 

[wca_tim]

Re: Changing Ignition System on 89' 5.7L GM Mercruiser

if you've a major problem, there are often whole set ups or at least distributer and the associated ignition module for sale used for 100 or less. and to be fank, I'd replace a gm hei ignition with a tbolt iv long before the opposite