I have read the manual for the Evolution 15cc GX but I cannot find where it tells me the correct prop size for breaking the engine in.

After breaking it in, what prop size would be recommended for the Sig 4 Star 60?

Thanks.

Finally found it. 13x6 for break in and 14x6 after that.

Jeff, there have been a lot of questions about this engine, I haven't seen anyone using one yet so I went into the gas engine forum and found several pages just on this one. Guys have been doing a lot of testing with it and have most of the specs you would want. Even some you may not want. Looks like a pretty cool little gasser.

Where is the gas engine forum, looked but did not find it.

It's in the giant scale box. It has several places you can go from there.