Offshoreonly.com - Ignition coil question

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Ignition coil question

Is there anything special about the ignition coil on a TB IV system? Can a go to local parts store or do I need to find a marina.
1992 4.3L mercruiser Alpha Carbureted.
Thanks

SB will chime in ............Id run the OEM coil with the TB ignition, I had problems with the MDS ones..........I may have one, whats the part #

Quote myself:

Quote:

However, when it’s built correctly it is fine with the Tbolt IV module. Tbolt coil spec is .6-.7 ohm. Blaster II oil and epoxy cannisters .7ohm.

Resistance usn’t added internally or externally like the old days of 1.5ohm v8 coils and 3.0ohm 4 cylinder coils.

It’s simply resistance of the primary windings themselves.
The modules control the dwell of the spark per rpm so nothing ‘burns up’ at slower speed (lower dwell) and provide more dwell at higher speed along with a large current limiter setting to provide better spark at higher rpm.

The module is made for s certain spec coil, and that, again, is made for .7 ohm primary resistance coil. A coil with lower value will burn out the module and a coil with more resistance will provide less spark energy , again, because module made for that certain value coil. https://www.offshoreonly.com/forums/...lies/smile.gif

So, under .6 ohms primary will overheat / damage module. Over .8 ohms will make for a lower power ignition than stock. Typical 1.5 ohm much less power and 3.0 ohm crazy amts less.

So check with your parts stores. Most older guys are gone from parts stores, good luck on this stuff (canister coil primary ohms resistance) with the recent crowd. Lol.

I got about 6 yrs out of a blaster coil 2. Seemed to make good power. Tip... Chang the Coil to Dist wire anytime you change the coil or at least have an extra on board. The Flame Thrower 2 coil is .6 ohms. I have one but not tested it yet.