Thunderbolt IV issues

[Dogdave]

I have a merc 260 with a thunderbolt IV . I have had 2 used advance modules go bad a new one is $500.00 has anyone tried the MSD ready to run distrubutor?

 

[Bondo]

Ayuh,.... The Delco EST is the go to marine replacement ignition,.....

 

[Dogdave]

Thank you. I ordered one today

 

[achris]

Just be aware, it's not a 'pull out - drop in' swap. You need to make quite a few changes to the wiring harness.

 

[Blue Mist 97]

Retired my old Thunderbolt V to the parts bin last fall. Went with Davis Unified Ignition (DUI) marine distributor. One wire hookup (built in coil), two if you want to hook up your tach. It's about as easy as it gets. Stab it, find your 12v hookup, change your plug setting to .055, set the timing and done. $319 and free shipping from Summit Racing. I also opted for the Davis livewires, but my old wires needed to be replaced anyway.

http://performancedistributors.com/p...-distributors/

Forgot to mention, had read that there were some problems with MSD ignitions, but others said that they had no problems. You just never know, MSD would have been my second choice.JMO...

 

[NHGuy]

That Davis has the stongest available spark voltage and is supposed to be super easy to install.

 

[Blue Mist 97]

No Title

Yep to both. Big spark with 50K volts. Again, super easy to install and those who want to color coordinate, the cap comes in red, blue, yellow, black and clear. Best part is, you give them your engine specs, they will curve it for you (no extra charge) when you order it. No buying spring kits and having to test to make sure it's correct. Standard curve for my stock bbc engine initial timing set at 12* (their recommendation) and all in at 24*@3000 rpm. Heck it started easier and ran better just on the muffs. Hope to have it in the water next week for the first time and get a clear picture.

 

[achris]

What about shift interrupt switch? Provision for that?

 

[alldodge]

More voltage. bigger and hotter spark all sounds great just reading about it. What happens if the extra/hotter spark causes the fuel to burn faster? More voltage is not necessarily better. maybe the extra voltage means the wires burn out faster or need different ones, don't know?. If the fuel does burn a bit faster is there any preignition that "might" happen? What about the spark curve of the distributer, is it the same?

These and maybe a couple more might need answers before I jump in.

New and improved doesn't always mean the old and inferior was what we use to use

 

[thegoat86]

What about shift interrupt switch? Provision for that?

(agree and second the question)

 

[Blue Mist 97]

What about shift interrupt switch? Provision for that?

Yes. That was one of my questions when I talked to them, but the Bravo One does not use a shift interrupt switch, so a moot point for me.

I don't know much about alphas, have never had one. DUI owner Steve Davis stated to me in an earlier email about wiring the shift interrupt switch with the DUI.

On Alpha systems, for the shift interrupt to work properly with the DUI distributor, splice into the negative (-) side (brown wire) of the DUI coil which is inside the cap.

He did not say which wire to use, so I can only assume that the splice would be made using the black wire from the shift interrupt. Yes? No? Maybe?

 

[achris]

On Alpha systems, for the shift interrupt to work properly with the DUI distributor, splice into the negative (-) side (brown wire) of the DUI coil which is inside the cap.

He did not say which wire to use, so I can only assume that the splice would be made using the black wire from the shift interrupt. Yes? No? Maybe?

And there goes the 'Marine' rating...... :angel:

(for the wire to pass outside to the interrupt switch it defeats the 'explosion proofing'....)

 

[Blue Mist 97]

Yep, you are correct. Took the time to call DUI this morning. Guy who answered, stated that you could tie the shift interrupt into the tach lead and not have to open the cap. Don't know if that is proper or correct. Different story than the first time.

Sorry I brought it up. Won't happen again.