Hi guys,
Im getting back into the sport and have a NEW Os.46 FX on my spacewalker, how should I go about breaking in this engine? Im into nitor cars and have experience with engines there. How do I break in an airplanes engine... I suppose you do it on the ground right?
Is the first tank just idling the engine? Then what? When do i begin to tune? after 4-6 tanks? Which are which needles? Thanks

Hi!
Just let it rew fairly hi. Put on a 11x6 APC and after some 4-6 tanks you can let it rew at it's max.
That simple!

I broke in my 46AX's by starting them, and running rich. Then, throughout the first tank, lean the engine out so it peaks, but don't go too lean. Let it peak for about 10 seconds or so, then back to rich.

Repeat the process till the tank is empty.

After that, just fly it, but leave it a tad on the rich side for the first 3 or 4 flights.

Then tweak it and have a ball

Read the OS 46 AX manual and then you will know.....

Especially page 19 and on in the manual for breaking it in.....

http://manuals.hobbico.com/osm/46ax-manual.pdf

perfect answer.
there are many opinions on OS engine break in, but the best answer can be found in the OS instructions.