Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Bonjour Wayne,

If you don't see any screww, the flywheel is possibly sticked to the crankshaft with a kind of Loctite glue.

If so, it generally looses its properties at around 120°C, so a gentle heat of the flywheel could be a solution. 

I hope other members will give you other alternatives.

Be careful with heat on these flywheels. 

They are very soft metal.

I have used a small Pulley Puller in the past to remove them.