4 Blade to 2 Blade Props
 

I have read some of the posts on here about the difference in the prop size and pitch and they were very helpfull. I have a Megatech P-51 Mustang and it came with a 4 blade 8x8 prop. I was wanting to change to a 2 blade prop for improved efficeney. I have caught on very fast to the way to crash a plane and have yet to get a flight off that didn't result in a bent gear shaft and or a bent prop. I was wanting to change to a 2 blade in hopes of gaining airspeed faster because my plane likes to stall out. My question is what size prop should I use in a 2 blade model. The motor on the plane is a speed 380 or speed 400 one of the two. (I have seen both of these motors listed on this plane before and am not shure which I have.) If it makes a difference the wing span is around 3 ft. (Just to give you and idea of the size of the model.) If anyone can help me with this I would greatly appreciate it. I am about to the point to throw the bird in the trash and move to another hobby.

4 Blade to 2 Blade Props
 

Don't give up or you'll miss a large gob of fun. An 8 X 8 prop for a 350/400 motor is weird to say the least. It would take a .40 glow engine to throw that much lumber or plastic around fast enough to fly something. Two blades should certainly be enough even if they don't look as scale as a four. If the 4 blade had a pitch of about 2.5 it MIGHT work. A two blade7/8 X4 will probably work. I've used 8 X 4 power point wood on a 500 speed ungeared and even that was too much of a load. Another thing about two blades is they move in less disturbed air. The lower pitch will give you more RPM which is the name of the game if you stall a lot. You didn't say whether or not your setup is geared or direct. A geared motor will turn a larger prop albeit slower. I suggest you also check the CG which is too often a cause of stalls.
Stay with us. RC is the most fun you can have while standing on the ground.

4 Blade to 2 Blade Props
 

ahem...I would to encourage you to stay in the hobby, but if you insist, please look me up before you toss the bird. I could always use a good first plane.