(quote)FILE IFR
4 strokers smile and run well with a heavy weight prop like a Graupner. Light weight props like a Master Airscrew and wood ones are undesirable.
NO!
MAS props work great on any engine including FStrokes and wood as well, if your flying a tail dragger then MAS props are durrable and can survive prop strikes, wood on the other hand are toothpicks in the making whenever they touch the ground

(quote)MinnFlyer
Try tuning it by ear before buying a tach. Some guys can't tune a 4-stroke without one, but nobody I know needs it.

if its your first 4stroke, get the tach it makes tuning much easyer for the first timer, once you have heard the sound of the engine changing rpm( there is little if no engine sound change frankly) then the choice is yours, its easy to get a lean run thinking your needle is set right, when the engine is on the lean side, I always use my tach on the first run of the day to set the needle after that its fuel and go.
on my 91 and 120 OS FS engines I get about 9,800 top RPM's back that off 300-500RPM as you richen it for flight, you will get those RPM's as the engine unloads in the air durring flight, if your running top RPM's then when the engine unloads you can get the floating like posted earlier,better to run a bit rich than run to the repair shop.

I use Coolpower 10% and they run well also