Norrie asked me to place his update here. He has some problems with attaching the images ... (pictures will follow soon)
Fellow Einzlinder Enthusiasts
Following on from the above I now believe, with fellow forum members suggestions, that the staining on the underside of the exhaust rocker cover was caused by old oil in the pushrod which I failed to clean out properly despite using solvent, a piece of wire and compressed air. As mentioned the exhaust tappet clearance was opening up significantly so I removed the head and noticed that the lower end of the push rod was breaking down and starting to collapse. I couldn’t see any debris lying on the cam follower so replaced both push rods and optimistically, as I wanted to use the machine during the beautiful 2018 summer, carried on riding
Having covered approximately 1500 miles on the completed machine and feeling that all was not quite right inside the engine e.g. there were some interesting noises under load, compression was low and the oil consumption was spectacularly bad. I was never happy with the re bore I’d had done and planned on replacing the piston and barrel with parts from Germany curtesy of Taz’s courier service when she and Marie were over last August – thank you both very much.
On removing the barrel I discovered that I should have been far more critical in my earlier assessment and investigated further
Photo 1 shows the original push rod breaking up and not having removed the barrel previously meant I was unaware of the damage being done to the cam follower, presumably caused by bits of push rod (photo 2). Fitting a nice new push rod against an unnoticed, at the time, worn cam follower (photo 3) and valve adjusting screw means that the push rod takes on the shape of the worn components and wears prematurely.
The top piston ring was stuck in its grove and the middle piston ring was in six bits explaining the low compression and high oil consumption.
The sump and oil pump have been removed, dismantled, cleaned, checked and with a new cam follower, pushrods and valve adjusting screws ordered. Once reassembled with the ‘new’ barrel and piston I am looking forward once again to flying along the road in glorious sunshine (hopefully)
The moral of the story, for other apprentice Einzlinders like myself, is to critically check absolutely everything as some 50-60 year old components, especially if they have been lying around for years and if from an unknown source, may no longer be suitable for use.