Poured petrol/2T mix into the left reed inlet and straight away the right side crankcase filled up to the same level.

Poured the same mix into my spare 88 year engine which wasn’t properly stored/air tight and not a single drop of liquid passed to the other side.

89 year engine down and 88 year back in and motorbike is idling fine with no hanging or increase in idle. Both cylinders warm up while reaching operating temperature and same exhaust notes from both silencers.

Very well done for a maybe 34 year old centre seal.