After running Stalkers almost exclusively for about 20 years, and using 0% FAI fuel with all synthetic, I am a bit bewildered by the concerns being voiced here.
Engines designed to run 0% nitro are not, in my experience, harder to start than other engines. I start mine in the following way.
I place my finger over the venturi, and flip through 6-8 times. After this prime I flip through as i lift my finger from the venturi, thus sucking in that last slug of fuel into the engine.
Next, I flip through an additional 6-8 times to atomize the fuel in the engine.
The engine is now ready to start.
I attach the nicad glow driver, and while holding the prop firmly, I'll slowly pull the prop through, and feel for the "Bump".
No bump? Start over from the top.
You have a bump, then rotate the prop until you feel it come up to compression.
Signal a start, if your making a competition flight.
I use my fingers and hit the prop clockwise back to, but not through, compression.
I get almost 100% first flip starts this way.
Unless you are running an old Classic engine where high castor fuels are needed, 10-15% synthetic/5-10% castor is all that's needed for many modern engines. Speaking of Stalkers, I've never run more than 18% all synthetic. (normally, 17%)
I feel that I'm getting the power I need, and I'm still running my first Stalker regularly with no problems.
John Miller