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Prop recommendation for RaceStar BR 4250 800kv motors


Does anybody have any experience with this motor, Race Star BR 4250 800kv? The specs recommend an 11x5.5 on 18.5v (5s), but yet says it is acceptable to run on 3-7s. I’d like to run it on 4s and an 11x.5.5 prop seems a little small. Planning to install these in a fixed-wing twin engine tractor configuration. Any suggestions/amp draw data would be helpful.




Wake up! Time to fly!
from Racerstars web page for the motor there is only this.


Brand : Racerstar

Model : BR4250 800KV Motor

Working Voltage : 3S-7S 18.5V

Load Current : 48A

Recommanded Prop : 11x5.5 inch

Weight : 210g

Recommanded Parts(not included)

Prop: click here

ESC: click here

Package Included

1 x Motor

I will assume since there is such a broad voltage range that they have not done complete testing like other manufacturers for prop combinations. It looks like the link for esc's is active though so maybe using that and doing some maths you can figure it out for any specific combination. Others may tell you to test them on your own using a wattmeter.