Take a look at the
Bike Kitchen in SF CA.
Similar bicycle co-op projects have been in place for many years. But bicycles are not subject to inspection for road legal status.
Motorcycles require much more liability insurance,
likely the need for certified mechanics and repairs/maintenance that need to be up to road safety inspections for all work done.. which would cut into your overhead cost... even more costly when something goes wrong on a repair work and you're sued for it.
Local retail motorcycles stores are not likely to enjoy having a co-op around that compete with their business. Make sure you have a good supply of consumers or comunity of motorcycle enthusiasts.
BTW, you don't want to work on your bike when you're buzzed or drunk.. bad idea.