RE: Super Tigre 90 propeller advice
A 14 x 6 is one prop that you can use, and it won't hurt the engine. It depends upon what you mean by "more pull". If you mean more static thrust, then the 14 x 6 will be OK. We usually, though, go for more RPM, and would investigate a 12 x 8 prop or so...turn the engine near 12,000 RPM and use whatever prop will turn that RPM and fly your model the way you like it. Too many people put too-large props on the G-90 and turn it too slowly. It runs very well in the high 11,000's and the carb works nicely when the engine's propped for that RPM.