Thanks for all the responses. All very good info (got a little off subject with the shaky Saito stuff but its OK........ Its all in fun)
Anyway, the reason I mentioned the amount of smoke it made was incase those of you who are familiar with 4S engines might realize the engine is set rich,and not quite broken in. So if 10300rpm was weak that could be the reason why.
The engine is going to be used in a .50 sized Zero warbird. I wanted a 4S for the sound and I'm willing to sacrafice vertical performance for speed.
Artisan, I will try the 13-6 prop, but would I get the same effect by going up in pitch instead of diameter? (as a side note,I originally had a MA K-series 12-6 prop on it because it looks better but I could only get 9600 rpm out of it.The APC out performed the MA by 700+rpm!)
Another issue is because of the short nose of a Zero (and probably because its a cheap ARF) I had to add a whole pound of lead to the nose to get it to balance. AUW is 7lbs 8oz. At this point buying a bigger engine is not an option but I wanted to get an idea from some experienced 4strokers how this engine compares to others of similiar size and if it has enough omph to pull this weight.
And finally maybe those of you who have several engines (2s &4s) might create a reference post with practical rpm figures of what your engines are capable of with different sized props. That way when a modeler like me with no experience with 4Ss will have a real world reference to compare the various engines that are available.

Thanks again!,
~Jay