Ok I'm wanting to after crashing my GWS Zero rather than buy another gearbox/motor combo for it I want to put a .049 or something on it. I figure with gas power and a fuel tank I can get much longer flights with more power. The birds weight right now is around 14 ounces but will change with the motor change for sure. Especially without the battery in there. Would a .049 be a good choice? Stock setup is a geared 370 electric so I figure an .049 will really drag it down the road good. But I'm new to 1/2A gas stuff I've only had experience with .40 sized gassers and small electrics. Any help will be greatly appreciated.

I have looked at these Zeros, they don't seem to much different in size and weight than the Ace Simple Series. Like all the conversions I have done, it's an experiment. The first obstacle I noticed on that Zero is the front cowl, you won't have a 9x6 or even an 8x6 to get some air moving back with a 1/2A engine. You will have to put a 6 inch prop in front of the cowl and see if you get enough prop clearance to creat any valuable thrust. Just because of the front face alone you may need an .079-.10 size engine minimum just for the size of the prop needed. As for the weight, my .061 is flying a 1lb 5oz flying weight mini starjet, so your weight is not a problem.

The weight of the battery and motor is alot more than the few oz of a Norvel and won't make near the power for the price.

How much room is in the fuse for a fuel tank?

The fuse is full of room. There's also the battery tray with runs from the front of the fuselage all the way to the back of the canopy. How large of a prop will an .061 turn?

If you give the cowl more exhaust area than inlet area the prop just in front of the cowl will propel the plane just fine!

6/3 maybe a 6/4 if well broke in...I don't see any problems converting it..maybe others can comment but i would'nt use any less than 16 or17 once torque servo's for the fly surfaces...hitec hs-55's or equivalent..
Good Luck..Aaron

Thanks for the advice everyone. As far as servo's I used over rated servo's to start with. Their mini's and the aileron is a BB I belive their rated at 24 ounces.