To pick up on Ian’s point about small end (lack of) lubrication.
‘Ears a goo (as we say in Birmingham), some Scott owners believed in the practice of fitting “stuffer blocks” in the crankcase under the pistons to decrease the lower chamber volume and promote better gas transfer – which also had the effect of displacing the inert volume under the piston crowns thus creating gas flow to both aid cooling and increase small-end lubrication.
Other Scott owners didn’t bother and just listened to George Formby records.