Need thoughts on chain-driven siren

[Mac]

So, I have a pretty large chainsaw that I never liked much and basically stripped down to the engine and sprocket. I'd like to make it power a siren somehow!

My thoughts so far, would be to run a long bar through a rotor, and onto bearings on either side. The stator in the middle of the bearings\mounts attached to the base somehow... then a sprocket on the bar, with a chain running to the motor that can be mounted to the base as well...

Any ideas on this? I know its not useful- but i've wanted something fun to do with this engine for a while.

My only concern at the moment, would be starting the chainsaw- while a rotor is connected via chain. I'm not sure if that would cause problems ?