The great circlip caper
Readers or perhaps sufferers of ‘In Balance’ will have read about that heart-stopping moment when I thought I’d not seated a piston circlip properly and had to dash out on Christmas Day to inspect the engine closely. A few of you suggested it was just my way of legitimately spending time in the shed on Christmas Day, but even more of you admitted to your own ‘moments of panic’ in such circumstances. So, here are the two pictures that caused the Christmas furore – clearly the circlip can be seen not seated correctly and the next pic in the sequence shows the barrel in place and the ‘did I, didn’t I’ thought surfaced. In the end I had seated the circlip but well…
‘tray’ and laid out all the carburettor bits in sequence. This was helped by remembering to photocopy the exploded diagram from a manual showing the assembly sequence. If I can suggest a tip to do then this is it, copy a diagram, blow it up to twice over the size and lay it next to the carb as you assemble. The tools needed to do the job had been pre-cleaned and I’d even checked to see if any special bits of kit would be needed… it would be nice to claim I was always this organised, but I’m not and I might as well be honest about it. However, the assembly went smoothly and the carb looks good on the back of the barrel.
Before that, the engine was assembled and quite a bit of care was taken over heating cases so cold bearings would drop in rather than having to be forced. The gearbox went together easily, the crank slipped in with the help of a puller and the cases were closed. Then came the barrel and the (almost) great circlip disaster. Once that was sorted I slipped the engine in the frame before starting to hang other parts on, such as the ignition and clutch. It would have been possible to assemble the lot on the bench but that would have made the engine twice as heavy and fitting it to the frame means it is securely held while parts are attached.
Now, we could liberate some of the new bits that had replaced those parts too worn out to re-use. Things like the kick-start idler pinion and cog, which are those bits that suffer abuse in the life of the bike and it seems were very rare, but a friend found the shaft cog on his spares shelf and CMS NL had the last possible idler pinion in existence. Okay, we could have had one made, but we got an original part. It also seemed a good idea to start temporarily adding bits to the rolling chassis so we could remind ourselves of what was missing, what went where and what we’d have to search for.
In the main assembly went okay, as I’m sure most people who’ve looked after their own bikes will know that you do get a feel for what should go where and what maybe needs taking off and turning round. Just such a thing was the exhaust pipe top bracket, which foxed me for a bit. It rubber mounts the pipe and has to go on a particular way to mount through the tapped hole in the frame. The problem is it fits the other way too and
pushes the rear of the pipe a long way out. Stuff like that is where the sketchpad or the photo album comes in and a glance through the images showed the error.
In an assembly such as this there are often sequences to work to in order for assembly to happen. Having had the bike as a bodywork free rolling chassis for some time it was obvious that the various plastic undershields protecting the airbox area from dirt and muck should go on before the whopping great rear damper. Luckily, a couple of bolts hold the damper and it is a simple job to whip it off and add the plastic and then the damper. But such things are part of the fun of rebuilds; at least that’s what we convince ourselves when we’re busily cursing in the shed on a cold February evening. )