W/E 12th April 2020

extra shim

So left the garage last time having decided I needed to swop the cylinder head off the spare engine onto Atlas #1. Once again I learned the value of walking away and thinking. Came back with a fresh pair of eyes and challenged why it was the exhaust cams could not be changed between Atlas #1 and Atlas #3. Fiddled for a while and then spotted the obvious which was that Atlas #1 had some shim on the centre support bearing. I removed this and the cam now works in either motor. There is no shim in Atlas #3 and I can’t see any reason for it in #1 so out it goes! The cam isn’t the smoothest but it should be ‘good enough’.

damaged bearing and camshaft

Bad news was waiting when I finally took the inlet cam out. I can remember butchering the white metal bushes when I put this engine back together many years ago – there’s evidence of my ‘handy work’ on the exhaust cam bushes but this was a new (low) level. The bearing surface on the cam is now damaged. As with the whole mess I intend to try and start it as is and once its going return and replace both cams with the pieces from the spare engine.

Suspension bush

Finally I went back to the suspension knuckle and in the first instance ordered up a replacement bush. On closer inspection I can see that the reason the steel bush dropped out is that the plain bearing pressed in to the knuckle has worn thin. My original plan was to maybe loctite or shim the steel bush but if I’d have done that the bolt going through the bush would’ve just worn the hole oval or in a worse case broken causing suspension failure! The reason for the wear is dirt getting in behind the o ring seals – something to bear in mind and maybe introduce six monthly checks on condition – especially if you’re going to use the bike all year round.


I dug out a bent frame I had in the back of the garage to salvage the swinging arm. The non-standard stickers look cool + the rest of the paint is in good condition. I can use this swinging arm in the build and save time not having to get a rattle can out.

Nick 🙂

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