How would you trim down this metal prop?

I’d love to cut it down by 10mm to reduce force on the motor. How could I do it easily ?


I think it will be difficult without a lathe. It will easily become very unbalanced.

I cut it down by 20 mm and surfboard did not have enough power
after 5 minutes I changed into one uncut
your engine will easily handle this propeller
its only major drawback is its big size and weight

If you cut it down you should then balance it or you may introduce wobble which can cause your shaft seals to leak. So the actual cutting is just the beginning of the process. Not that hard to do but does require the right tools.

Hi, i would recommend a prop with a higher pitch, so you have a better efficiency at higher speeds. I had very nice stats with a 7 7/8 x 7.5 honda 5hp lathed down to ±140mm.(still have to record the wattage at high speeds) but I easily rode 30kmh with duct and was able to max out my scale(32) at 1800watt.

I just put it on a lathe. Be careful to lathe it with very small steps(0.5mm) per stroke at a very slow lathing rpm. The larger diameter aluminium otherwise easily cuts into the knife.