Bore sizes (and stroke) are nearly always quoted in mm.
The capacity is in cc, after all.
The French had a lot to do with early engines !
(but oversizes are nearly always quoted in thou oversize).
Its a mixed up world, isn't it.
1 mm is approx 40 thou, so your cylinder is pushing 100 thou oversize,
which sounds like a lot !
I have no idea what the maximum oversize would be though,
can you see daylight anywhere when you hold it up to the light !
You sometimes see cylinders where you can see the sleeve through the fins...
If its held together this long, you could probably sleeve it back to stock. ?
Racing it may not be advisable though.
