Scoutboy74
Moderator
.16 of an inch would be way too wide of a spark plug gap and probably not even possible without breaking the electrode. .016 of an inch isn't wide enough. The correct spark plug gap is .035 (thousandths) of an inch. But, the question posed wasn't what your spark plugs were gapped to. Rk wanted to know how big of an air gap to ground you observed the spark jump. A strong spark should have no problem jumping a 3/8ths inch air gap to ground.