Drawing on my automotive experience I'd say said scooter unless its a top of the range burgman or something probably has a simple setup with a carb and an electronically assisted magneto for ignition.
One important consideration if the transmission isnt variomatic ie there are 'gears' then you need to lock out remote start if the scoots in gear.
A raspberry would do the job, personally I think an arduino would be a better choice, for size & power consumption, something like an Attiny, security is also a concern, a rolling code system would be a good start.