electric winch? wouldn’t that need even more power? 
Put up a picture of it, sounds great! The Boma motor is a large in runner for e-bikes right? do you protect it from water in some way?
Just did a test run, using a yamaha low pitch propeller, and it was much better than I expected, the top speed was amazing, according to the gopro when I was at 3/4 throttle it was 30kmh, i went nearly full throttle once after the gopro was put away and it felt like at least 35kmh 
I really expected the 7 1/4 x 5 propeller to be extremely slow, but it was fast and efficient. Rode for roughly 22 min down to 3.78V per cell on the battery (20AH 12S).
Verdict: BETTER than double motor. Video to come!
Mat: Thanks for introducing the 80100 motor DD on the forum, you were the first person to do it so deserve some kudos 
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Well done !
Which ESC did you use ?
I used the flier 400a 22S boat ESC, Im using the water cooling, it didn’t get ‘luke warm’ just a few degrees warmer than what it would have been if it were not being used
That is great! Do you have a Solas prop for comparison as well? Would be interested how it performs compared to the lower pitch yamaha. I have a 80100 laying around waiting to be prepared, haven’t decided on a prop yet.
Your speed results somehow contradict @borntosurf222 's calculations regarding the 80mm motor, or not? Drag doesn’t seem to be much of a problem with that speed and range you are getting.
didn’t seem to be an issue at all, its quiet streamlined, maybe his calculations were for a flat 80mm circle? Ill have a video up in 25 mins so you can see.
I don’t have a solas prop, but I might order one for testing so we can compare.
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So you are running the Yamaha 7 1/4 x 5 without modification and without Duct ?
no duct, made the bore 12mm and grinded off the top maybe 10mm so it would slide onto the shaft fully and be bolted on the end.
heres the vid: never went full throttle in the video, only did after I put away the gopro 
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Looks like its flying! Get a GPS on there to measure the speed
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The Gopro GPS can be pretty accurate for very constant speed, from my experience you can even add several kmh on top, so he was maybe faster.
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But depends on which gopro you have…
I don’t know about any difference, I would have guessed the Hero 5 and 6 have the same sensor, I have the 6 and it seems to have a 1 Hz sensor, no 10 Hz, so varying speed is a problem.
But that might be an older one without GPS too
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That sounded like it has GPS 
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Its the hero 5, I only just got it so got the speed to work in ‘quik editor’ but i made he video in iMovie and for some reason the dial didn’t save… top speed was 30kmh at one point, average of 25kmh mainly.
top speed 30 KM/h with a 100KV on 12S and 5" pitch?
its 130KV, 12s…20char
edit: 5" pitch
It would be extremely interesting to have an apples to apples comparison (same prop) to @Mat s 80kv. I have the 80kv too and wonder if it will perform better or worse. I thought the 7 1/4 would be slightly too large even for 80kv, so now I am confused 