ORIGINAL: rcs36
Keep the info coming guys. I am very interested in this topic.
I am a nubee to these gas engines and I am finding good info reguarding things that I never thought to concider before, such as the spark plug. I assumed that you just set the gap and torgue and go! I guess I should have known better because I insist on using only the best glo plugs I can get for my glo engines.
I bought an OS GT 55 and it came with the NGK CM-6 plug in its own NGK box. The box had the gap settings on it but I pulled a dummie and threw the box away before I set the gap on the plug. Just last night I was trying to find the correct gap setting and came up with a spark plug site that said .016 gap. So Question: Is the .016 gap OK for break in and then change to the .018 - .020, that TOM suggested, afterwards. I read last night that auto racers like to widen their gaps on their high performance race engines.
Thanks!
Racecar engines can benefit from larger plug gaps because they have a lot higher voltage to fire the plug across that gap. Our engines are not racecar engines! Our tiny ignitions don't have that voltage reserve.
Stick to TOM's recommendations and you can't go wrong. Your engine probably won't care whether the plug is gapped at .016 or .020 though I'd stick with the wider gap in my engine. Anything in that range will be fine though.