by RCModelReviews » Thu Sep 16, 2010 5:44 am
The very best plug for all the 4-strokes I've used has been the OS-F
There are other brands (Merlin, Fox, etc) but the OS-F gives best power, best idle, best transition and longest life.
My Saitos are still using the original OS-Fs I fitted after I broke them in and they're *years* old now.
My experience with the Fox Miracle plug is that it was colder than the OS and gave a rougher idle with less RPMs. It also seemed to wear out pretty quick -- getting increasingly colder over 10-15 tanks of fuel until it would no longer idle reliably.
Haven't actually tried the Merlin 4-stroke plugs but the 2-stroke ones I tried were pretty "average", not as good as the OS or Enya equivalents.
RCModelReviews.com, just the facts.