An Enya #3 is not a long reach plug. It is 4 MM. A Long reach plug is 5 MM and a short rech is 3MM. The japanese don't complicate anything. They make one plug reach for all their two cycle engines. What's wrong with using an Enya plug in a 4 cycle engine. That's what Enya recommends for use in their 4 cyc;les. It's the only plug I use in any of my glow engines. learned that trick while living and flying in Sasebo, Japan.