Well, I'd say it'll be the std 3600 rpm, and gearing (thus torque) is set up by the pulleys.
So an ordinary cent clutch will do.
If the tiller is still complete, you may want to take good images of all the pulleys and their arrangement.
Maybe there is a reverse gear mechanism you can just 'copy' to priceline.
Maybe the reversing shaft just drives an auger.. I don't know, but you'll see.
But keep in mind that the reversed shaft runs off the camshaft;
I'm not too sure that it can take the same load as the crankshaft, so be gentle
and use extra low gearing for that
I'm not sure a cent clutch is your best option if you intent to have a reverse gear,
there might be some sort of belt engagement (like a ride on mower clutch) which is an effective way to disengage the forward shaft and engage the other one.
With a cent clutch it'll be hard to disengage that driveline.
So I think using the pulleys and belts is an option if you want a reverse gear for your daughter.
'sid
PS Don't know but it kinda reminds me of a tecumseh engine.. *shrugs* But I wouldn't take bets on that
