Modern Vespa

can you use s stroke oil instead of gearbox oil temporarily i think my main bearing seal has gone the gbox oil smells of petrol and do you have to remove the flywheel to get the side casing off to get into it

Yes you can use 2-stroke oil if the clutch side seal has gone , But this is a temporary fix ( plus will smoke bad )

It's an engine out job and full engine rebuild while your there , As most things need coming apart so you might as well do this