I'm in the process of getting a recently purchased ES 250/2 to a rideable state. I've replaced the mounting blocks under the engine, which were allowing the engine to rest on the footrest bars, wearing the casings and transmitting vibration through the bike, also it seems causing the clutch to lose adjustment and slip badly after a short distance. Now that's sorted, I have a regular clatter in first gear, related to engine speed, disappears in other gears, the gear change seems ok up and down.
I can hear a clank in first if I push the bike with the clutch pulled in engine off.
Is this bike safe to ride or is the gearbox about to self destruct? I changed the oil and there weren't any fragments, but I don't want to have a lockup as I tootle along. I had a new ES in about 1971 and don't remember any clattering then.....