most of the guys who tune there 2strokes at our club use the pinch test to tune not by ear, this same debate was pummeled to death a couple of months ago and its now resurfaced again, with the same arguements against a tach.no real reason not to use one just "you don't need that kid" and some chest pounding about how they can do it without a particular tool, a bit goofy really[sm=spinnyeyes.gif].

I use a tach on my 4st engines which are the majority of the type I happen to have, all the guys at our field who have used 4st engines recomended using it and its a handy tool it really eleminates the guess work out of tuning your engines, something I do every flying session( adjust the high speed needle) by peaking the RPM and backing it off a few hundred so when the prop unloads it doesn't overheat the engine.

I pile that sort of advice into the same junk bin as the,"you don't need that engine manual just do it my way and you will be fine son" mentality,I call it poor .

for a beginner just starting out get a tach. use it familiarize your self with the tuning and running procedures, learn the engine inside and out and if you don't need it later pass it on to the next guy/girl who is just starting to learn the process of tuning there engines.

4strokes are not cheap, and a extra 15$ is worth it to me, and the planes I happen to fly with them, there not cheap as well .

valve adjustment kits don't come with OS engines now, there 12$mine sits in the corner 11 1/2 months a year, I get more use from the tach for sure.

I have checked the valves on my newer OS 91's and they have all held there adjustments even after break in runs, just like GB stated once a year is about all they need just to be sure.

4st burn less fuel and are cleaner,alot less slime and the small amount of oil is burned more thoroughly than on a 2st, I like that as well

matter of fact I am going over the fleet now, doing my pre season clean up, valve checks, and EZ fueler maint. checks for flying season since we just got a new field
the only ones that needed to be adjusted were a couple of the engines I got off ebay after adjusting they ran great,(my gain).