Which ones are better ? to be use on a merc 2.5, 200, carb ponny ?

On my Pro Marine set ( looking at the center of the cable adn it's a carbon core ) I check the continuity of those cables (6ea.)with my multimeter and
there was no BEEP at the tester.

I'm thinking if a set of Solid Core would produce a better spark ??!!

Thanks,
Boat Doctor