Electric Yamaha SuperJet Build

Hi all.
I have started a conversion of an old superjet 650. I will use the new liquid cooled QS138 90H and a Votal 200/2, not sure if the controller is to small but I will use it as a start and upgrade later if needed, the controller will be modified to liquid cooled in some way and I also plan to have liquid cooled battery. Motor will be direct drive on the pump shaft with the flexible coupling.

Cool project :thumb:
Controller is too weak I think. If you plan to upgrade later, make sure your battery pack will be able to handle that.
I will follow your progress. Good luck and enjoy building!

After test mount of the the printed coupler I ordered this piece of machined Al 6061T6. Very well made and fits like a glove.

Cooling, for first test run I think I will just have the motor liquid cooled. I added a strainer to the inlet and will run the seawater directly in the motor without heat exchanger. The inlet is pressurized from the jet-pump. One thing I’m not sure about is if I can use the bilge pump outlet as a cooling outlet. The bilge is meant to suck water with under pressure from the jet pump. It will be like a push and pull in the system, any thoughts?

The insides of the motor might not like salt water. The manufacturer might have some advice on that. You may need to use a heat exchanger and keep distilled water in the motor. I'm sure it would work for a while with salt water, but could be bad long term. Flushing out the system with fresh water after each use will help.

Awesome build! That controller/motor combo should be great for a small adult and kids. Controller should not have any issues with heat. I worked with the guys from https://www.electroandcompany.com/ to get my controller dialed in and maxed out on power. Worth it if you are not familiar with the votol software. But so far heat hasn't been an issue. Your water lines are also fine going in and out where you have them. Another tip will be to make sure you have the right impeller and your impeller clearance is within spec. (if not you will need a new wear ring as well).

Not a Superjet, but might give you some ideas.
https://endless-sphere.com/forums/viewtopic.php?f=39&t=116058

Thanks for your feedback, regarding the cooling I will mostly run in lakes and if I take it to salt water I will flush the system afterwards, adding a zinc anode connected to the inlet might protect the motor a bit.

Maybe I should try to find a better controller, any advise on which one I can use to squeeze out the most of the motor?

I would stick with the one you have for now. I am not sure about the 200 but the 100 you can run it much higher then its rated for.
Also with the votol you have more control over the flux weakening to get the rpms up. And you already have it so may as well try it. A stock superjet runs about 6600rpms and makes 63hp.

Any updates?!