Hey Rab.. thats some serious polishing!! That engine should go to the moon and back.. I learnt on a 125TB (same engine).. its so under-stressed that you can hear it yawning!!!! Mine just used to buildup alot of moisture in the crankcase if it didnt get really hot at least once a week to burn it out… so lookout for signs of emulsifying oil.
To “ERR” is natural.. to really fowl things up needs a politician!!