Motor for my Yellow Jacket

[JohnZ]

I built this boat several years ago and want to get on the water this summer. This is a Jay Turner rigger design featured in RC Boat Modeler feb. 1999. How's that for procrastination?
originally built for a 540 ROAR stock motor and 6-7 cell Nicad, brushless/Lipo is what I want to use and need some recommendations.
The Feigao 540S seems to fit the bill, but what KV is best to use with a 2S Lipo pack? How many amps should I plan for with which prop?
The hardware is Octura and installed now just want to get the power unit set up to finally finish this thing. As far as speed, I don't plan to race it as there is nobody up here who is into racing in Northern Michigan...yet. But, I want decent speed and maybe a little more.....how about a couple motor recommendations for medium and hot set ups?
Thanks.

[Steven Vaccaro]

Anywheres between a 540 8s-10s should work quite well on 2s lipo. I would use a 120 amp esc. But you should be in the 50-70amp range.

[Fluid]

Our club runs similar-sized sport hydros on a 7L Feigao with an m440 prop. This gives very good speeds and should be a good place to start with the YJ. You can go larger on the prop but start there. This is a racing setup, for longer run times try an 8L or 9L. I'd love to hear how the rigger runs with modern power!




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[JohnZ]

Thanks guys. This gives me the info I need to finish it . I think I will go with the 540S series as that is close to the size of the old 540 ROAR motor. That way I can make the installation easier and keep the original layout. Will give the 8S a try I believe and see how it goes. Since this is my first rigger, I need to start a little milder and work up from there.
I'm not even sure if the boat will run properly, but nothing ventured, nothing gained.
see ya

[JohnZ]

I'm going to use the 540-8S so now which prop works best with this motor and 2S pack? I have Octura 1732 and X632 beryllium props. Will either of these work with this motor?

[Rex R]

personally I'd start w/ an x430...but, of the two you listed you always want to start w/ the smaller prop, in this case the x632.
rex

[tth]

John Z incase you dont know yet "Fluid" is the man who designed the YJ. Jay Turner. Also welcome to Offshore Electrics!!!

[JohnZ]

Thanks guys. Now I've got to figure out how to get 2 -2S 3700 packs into the boat. May have to do a little modification to the inside of the hull. The packs will be run in parallel of course.

[Simon.O.]

If it is any help I have a rigger that was designed for a brushed 05 size motor.
It was then setup with a 540-8S 4400kv Fiegao motor and a 432 prop fed with 2S lipo 5000mAh
The 632 is a much better prop for this motor and I now run the 632 with a 7S 5000kv motor. That is fun.

5000mAh is plenty for this setup and when I need new packs I will go down to 4500. but up the C rating.

I am now hunting for a 1732, 1930 or similar prop.

Hope this may hev been helpful

[JohnZ]

Simon, thanks for the info. I happen to have a couple 2S 5000mAh packs.
The new 45C packs sold through Hyperion look promising for sure and with a 5-6C charge rate they should make great batteries for heat racing.