briggs 12.5 duel plug

im building a briggs 12.5 ive cammed and ported it but im now thinking about putting duel plugs in it, how would i do it just drill a hole and tap it? also what type of coil would i use? would one off a opposed work? and is it even worth doing?

Interesting, never heard of this idea before

I don't think it's worth doing. I have seen the occasional 2-stroke with dual plugs, and the purpose was clear. Since they would foul so easily, the redundancy was created to get you home. I've seen it on a few 4-strokes too, and the purpose was far less clear.

In my experience with small OPE engines and the like, there's just no point. A good quality plug gapped correctly (or even a bit wide) on an engine that is in generally good condition, will do more than just fine. You don't want to split the output of one factory coil or magneto- Two half-assed sparks is NOT better than one good one. You're likely gonna be up the creek trying to mount two. Why? Think timing.

it dosent seem to me that there would be any real advantages. it could easily compromise the structure of the head. unless you get a HEMI head, i wouldnt bother

You can do it.. its pretty common actually.. but I recommend using hitchs head at hitch performance parts for your motor.. cones with all you needs qnd its pre tapped

not worth it if your not running alky or methenol if your running alky or methenol then yes go with the dual spark plug head BUT you will not see any proformance gains

dual plug, might as well go double valve too.. make it like a hemi