RE: engine prop size
Hi,Look at these boats on ebay their in scales and you'll see for your self that 1/8 is to big for your .21 motor.Here the ebay idam# 1/12 scale Miss bud like hydro#110028144978,the 1/8 bud hydro like 230023732275,Here your scale 1/10 that your .21 would go in to#140025305587 #16002584611 that the shock wave 36. If you want to do a 1/8 scale boat,you need a zenah motor its like a weed wacker motor. The higher the scale number,the smaller your boat will be=like 1/12,1/14.1/16 and so on. The lower the scale numbers the bigger your boat will be=1/12 1/10 1/8 1/6 1/4 and so on.Anything over 38 inc is to big for your .21.And anything under 27 inc is to small for it to.I see alot of boat with .21 between 28 inc to 38inc. I wouldnt BS you about the scale size,you can look and see what I'm talking about. I'd hope that this helps.[8D]