About twenty years ago I was asked by a local member to help get his newly restored 1929 TT Rep going as he couldn’t start it. I checked all the usual suspects, timing, spark, carb, plugs, plug leads to correct plugs, etc., and it was a dead as a Dodo. Eventually I got him to tow me, on the peri track of a disused airfield, and it finally fired and started, but would only run above half-throttle, and was severely lacking in power.
Eventually it was decided to strip the engine down. No cylinder base rings…..