Engine runs but is not moving. :/

[Harley59]

I have an 65 3 wheeler harley. It runs fine but it is not moving. The belt that is on the car does not seem to have any tension in it. It is also connected to a large pully connected to a coffee can type pully. On the belt that goes from the engine to the rear wheels there are some springs on that pully.

I cant figure out how to tension the belt, maybe the pully needs come lubrication?

Thank you

[bentaxle49]

maybe you have a worn belt?

[RideNGolf]

You shouldnt have to tension that belt... Are you SURE that the engine is actually running and not just turning over from the starter?