Model 50 silencer performance mod.

My first proper bike back in the 1960’s was a 1961 model 50. It was in very good condition, apart from the silencer which was badly rusted, but had an indicated top speed of only 70 mph sitting upright on the level. Then one day the exhaust noise suddenly increased. I stopped to investigate and discovered that the innards had blown out of the silencer. I continued my journey and to my surprise the top speed was 80 mph. Vibration at that speed was unbearable but the noise wasn’t too bad as nobody turned to look at the noisy motorbike so I ran it like that for a while. It would have been best to fit a bigger engine or gearbox sprocket to keep max revs down a bit. This is just a suggestion to any owner wanting a bit more performance at no cost. Main jet may need changing but I never thought of that at the time.