Eldias
New OPE Member
- Local time
- 3:03 PM
- User ID
- 35592
- Joined
- Feb 22, 2026
- Messages
- 1
- Reaction score
- 1
- Location
- California
Good morning OPE-ers!
I've been playing with the idea of building a jet-powered Stand Up Paddleboard for a few years now. I'm at the point in planning where I'm trying to firm up what sort of powerplant I'm going to want and thought I could use some help in thinking through the options. I suspect what I'm trying to find is a unicorn, but I think if anywhere can point me in the right direction the distributed years of expertise here might have some good pointers.
To start with I plan on using a 3d-printed Jet drive with a metal impeller. The fantastic dudes over at RC Groups (https://www.rcgroups.com/forums/showthread.php?2826297-FJD-3D-printable-Jet-Drives) have been hard at work for many years on a scalable jet drive project. The two top-size impellers are 65mm and 75mm each. One of the members has successfully used the 65mm drive with an electric setup on a SUP to put around their local canals. If possible I want to use the 75mm model and I want to move at more than a gentle cruise. I'm shooting for a minimum top speed of 15mph but 25-30 would be ideal.
I've considered using an all-electric system like the poster on RC Groups used, but that system has several significant drawbacks. The motors and Electronic Speed Controllers are heavy, expensive, and hot. The batteries are heavy, hot, and don't provide a compelling run time. I don't think electric is completely out of the question, the drawbacks make it not my first choice.
The other answer to all those drawbacks seems obvious: A gas motor! Relatively cheap, power dense, and a supremely long run-time for the weight carried.
So I think my question to the forums here is: What's the right gas motor for my plan? Frankly, I'm not sure if I'm even considering the right displacements for the goal speed and endurance I'm looking for.
I've considered chainsaws, but to get in to the 70-80-80+cc range prices start climbing pretty quickly. AliExpress has some compellingly priced 2-stroke and 4-stroke gas powered leaf blowers that fall nicely in the 80-85cc range but I suspect these may not have the torque to move a water column. The third flavor I've considered is small motorcycle engines (such as the Wildcat 80cc or Avenger 85CC at California Motorbikes).
I've been playing with the idea of building a jet-powered Stand Up Paddleboard for a few years now. I'm at the point in planning where I'm trying to firm up what sort of powerplant I'm going to want and thought I could use some help in thinking through the options. I suspect what I'm trying to find is a unicorn, but I think if anywhere can point me in the right direction the distributed years of expertise here might have some good pointers.
To start with I plan on using a 3d-printed Jet drive with a metal impeller. The fantastic dudes over at RC Groups (https://www.rcgroups.com/forums/showthread.php?2826297-FJD-3D-printable-Jet-Drives) have been hard at work for many years on a scalable jet drive project. The two top-size impellers are 65mm and 75mm each. One of the members has successfully used the 65mm drive with an electric setup on a SUP to put around their local canals. If possible I want to use the 75mm model and I want to move at more than a gentle cruise. I'm shooting for a minimum top speed of 15mph but 25-30 would be ideal.
I've considered using an all-electric system like the poster on RC Groups used, but that system has several significant drawbacks. The motors and Electronic Speed Controllers are heavy, expensive, and hot. The batteries are heavy, hot, and don't provide a compelling run time. I don't think electric is completely out of the question, the drawbacks make it not my first choice.
The other answer to all those drawbacks seems obvious: A gas motor! Relatively cheap, power dense, and a supremely long run-time for the weight carried.
So I think my question to the forums here is: What's the right gas motor for my plan? Frankly, I'm not sure if I'm even considering the right displacements for the goal speed and endurance I'm looking for.
I've considered chainsaws, but to get in to the 70-80-80+cc range prices start climbing pretty quickly. AliExpress has some compellingly priced 2-stroke and 4-stroke gas powered leaf blowers that fall nicely in the 80-85cc range but I suspect these may not have the torque to move a water column. The third flavor I've considered is small motorcycle engines (such as the Wildcat 80cc or Avenger 85CC at California Motorbikes).
