Just curious if anyone has considered a gas powered board. You can get a 13hp (about 10,000w) engine for about $350, and then you wouldn’t need to get: a battery ($400-1000), a motor ($200-1500), a charger ($???] or an ESC ($200+).
It would definitely be louder, and a different experience. It would likely stick out of your board, and waterproofing it could be interesting, but it could potentially be WAY cheaper…
Difficult to run underwater. You would need some sort of transmission from the board down to the propeller like kardan, chain or belt. That would end up in a heavy construction.
It’s possible but would be a noisy as hell! I think that’s one of the beauties of the electric build. Everyone is amazed at how quiet they are.
Then there is “water transmission”… the Bruce Creation jetsurf convertible to jetfoil : replacing the electric engine inside the board to vacuum water up along the mast from its bottom inlet and expelling it from the rear of the board. Not sure about the efficiency though.
That would be in gfoil.builders.
I know. That was bad.
World premiere: if the gas (petrol) version sees the light of day, it will be thanks to the electric version 
There are a lot of pros and cons that I see.
Pros:
Cons:
Honestly, in my opinion electric is definitely the way to go, but was just curious if anyone had tried to go that route!
I am considering to build one using a Honda grass cutter engine (which weighs less than 9kg). There are some issues to be addressed like:
The reason why i am looking for this is cost! and it matters! especially when u see lot of e-foil owners spending handsome money on parts post purchase. Despite being so pricey it still cant work for 5 years without making a dent in pocket.
I think this can work. Let me make it clear i am tax guy no formal degrees in science, engineering and i may sound illogical but i am okay with it. And i do care about environment. But honestly in my country we burn coal to generate electricity! Period!
The grass cutter is a great idea.
How much power does it has?
Maybe a powerful chainsaw could work too.
I would keep it simple. Use a lower gear of a small outboard motor 2-3 hp range, its very simple to attach a shaft and a motor to it. The lower gear can be integrated to the the mast. The shaft is very thin on those, can go inside the mast. Small outboards have usually roughly 1/2 gearing, that is actually required to make a small gas engine work. Torgue is also an issue on those.
Actually think this would work well on an e foil, no more leaks and all electric parts on top of water.
Have been doing some testing on gas engine on surfboard and have noted that also a 3.5 hp ( 75cc 2 stroke ) outboard is sensitive to lack of torque. My tohatsu 3.5 really struggle with the Yamaha clone propeller with 8 pitch , same problem as the 65161 type motors also have. The problem is the diameter, not the pitch as such.
The critical moment would be to get it to fly, you would need low pitch propeller otherwise engine might stall. My gut feeling is that a Honda GX 50 might do the job with the right propeller and gearing, not sure a gx35 would be enough.
A Norwegian girl has foiled with a 4hp outboard engine
Simplicity at its best, brilliant! Thanks for posting. Of course not competing with an efoil, but very cleverly executed idea. Think Kotaro Horiuchi made a working foil powered by a 2hp honda 4 stroke, but that was a foiling boat so the lift of probably easier.
I have designed and am currently making a 2 stroke powered foil board. I have made the lower unit/mast and all of the drive components. Currently my biggest design problem is a one way check valve for the exhaust that will not allow water in them the motor is not running. I really wish I could find someone with a jetsurf to better understand their exhaust valve design.
This sounds interesting, do you have any pictures to share?
With such a 40usd board, that would mean a gfoil at the cost of … the foil 
, plus the noise
ps: we hardly see the transmission type between motor and propellor… any guess ?
…
Everything looks home made… a nice proof of concept
I will share photos as I get closer to having it complete
Hi, I had literally same idea, only with 4 strokes GX50.
I thought about forcing the exhaust through a mast. The mast would have to be custom made from aluminium tubes, which is not too difficult and definitely cheap. Biggest tube in middle would be for shaft and bearings, two behind it for exhaust. Somewhere in lower third would be dual exhaust ports. I also though about a one way check valve.
One idea was simple silicone membrane with slit in middle, like in plastic soda bottles on the bottom of the pipe. When the engine is off, the pressure inside of the exhaust tube is constant, therefore the water should have a hard time getting inside more than couple of inches. Advantage - it can be easilly tested, with a half-closed tube and silince membrane. Different silicone thicknesses can also be tested.
I plan to start my build later this summer, as I have no workplace now. I would be happy to talk more about it 
GL
What is the rpm of a 2 stroke power engine ?
I like your idea with the slotted silicone! I’m aluminum casting my mast/ lower unit so can add any number of passages. Right now just a vertical drive shaft and water cooling passage. The exhaust through the mast would be neat I’ve thought about that too but you’d have to make the mast thicker creating more drag and possibly too much back pressure when fully submerged. Would also still need some sort of check valve in the in case the water line rises past the exhaust output point.
