Atv engine for building a paramotor

[chickenbritt]

I have a Polaris 250 2 stroke and was thinking about using the engine to build a paramotor. What all would have to be done to the engine? Would it be overkill? 

[adamjedgar]

I dont really have any experience with retrofit but from my limited understanding often paramotor engines have a new crankcase fitted to allow for reduction drive mountings (eg gearbox or belt). Even though within usable limits, 250cc is getting rather large for footlaunch, but would be fine for wheelbase.

 

I am assuming that the motor you have doesnt have provision for redrive?

 

I think a second consideration is weight saving design features.

 

Finally, is the atv engine water cooled or air cooled?

Edited December 7, 2017 by adamjedgar

[chickenbritt]

The engine is aircooled and able to machine gear reductions for it. What would be a good size prop if I did wheel launch with that engine

[adamjedgar]

11 hours ago, chickenbritt said:

The engine is aircooled and able to machine gear reductions for it. What would be a good size prop if I did wheel launch with that engine

Big!

Props is a difficult one...its dependant on a number of factors beyond my experience. Things such as torque, power curve, rpm, cruise speed, cage diameter limitations, number of blades, efficiency, material its made from...

 

You could probably find a similar size existing paramotor engine and within reason, if technical and performance specs are similar (eg hp and torque curve), copy the reduction ratio and prop used on similar engine as a starting out point.

 

If there isnt anything to compare with, prop manufacturers are quite good at working out a reasonable starting point based on the engine performance specs amd redrive ratio. Chances are they have already made a prop for that engine.

 

 

Edited December 8, 2017 by adamjedgar