RE: 3W 24 gas engine thrust
Zinger props are best used as paint stirrers. Zinger Pro prop are for emergencies only. Get an apc18x6, or other quality prop (Mejzlik, MenzS, NX, etc.) and then see what you get. You won't get much more with that engine, I think the limit for a 3D plane with that engine is around 11 lbs.
DKjens