FH - assembling the inner timing case

 Lots of work faces now, but an interim look at the cylinder head reveals that the valves and guides are beyond use - there is a couple of millimetres of rock at the edge of the valve head, with the valve half out of the guide. 

So, while I wait for a new set of guides, valves and springs let's start on the timing gear. Fitting the pinions is straightforward once I have deburred the Woodruff keys. The timing is set to the marks:

I've cleaned the dynamo straps since you have to have the inner timing case off to fit them. I'll plate these at some stage if I'm not too busy riding the bike:

The oil pressure release valve has been through the ultrasonic bath and has a new 5/16" ball. The old one was grooved and rusty:

Next, for the record, the pump drive washer is fitted:

I've made a small spacer from gasket paper for the end of the pump. Each of the stud threads has been cleaned up and fitted with blue Loctite thread lock:

I've used the original deep nuts - I've flattened these and recut the threads, adding a chamfer:

If you read my last post, you'll know that there is supposed to be a thrust washer in the nose of the pump, under the circlip. It needs to be 14.5 mm OD x 2 mm thick.

I had a bit of 3/4" EN11 in the lathe to make a late-pattern QD hub nut spanner, so I've used a bit to make the thrust washer:

I've left the pip in it to make it easier to get out. Next, the pump drive lock washer - the inner tang fits in a groove (like a keyway only less deep) in the end of the crankshaft. The tang on the new one is much wider than the remains of the one on the old washer  - time to get the needle files out:

With that in place, we can knock the tab washer down. On the crankshaft, I have bent the washer over both the lock nut and the pump drive sleeve:

For the record, the cam drive tab washer is knocked down too:

I've also finished polishing the timing cases:

I had to clean a lot of carbon off the timed breather sleeve before it would fit, and relieve a pip on the outside. It's fitted with the thickest cork washer available (5/32") and the gasket is coated with Wellseal. I've only done the inner face for the moment as I will want to take it off again.

Test fit:

That's it for now. Next I will probably fit the dynamo drive sprocket and it's seal, but then to do any more in here I need the dynamo and the Automatic Timing Device. Both of these bits need rebuilding.

FH - oil pump

Over three years ago now I pulled this sludgy oil pump out of the timing case, planning to look at it and consider it for further use. It would barely turn.

Since then, much has come and gone (some of it twice) but I have stripped the pump and freed the high spots in the drive that caused the seizure. With these Mazak/Zamak castings, impurities in the alloy corrode and cause the casting to swell and crack, in this case causing high spots in the drive gear bore and damage to the circlip recess - though fortunately nothing irreparable. 

The body casting had a bit of carbon in the smaller bores:

The ultrasonic bath fixed that, and revealed some scoring. If this leads to excessive wet-sumping we will have to replace the pump.

With it all back together and working, I realised there was a thrust washer missing, which is supposed to fit under the circlip. I'll have to make one.

Charlie's Shed - Corks

This week, I have been mostly cutting up pieces of cork...

So while waiting for my fork tools to arrive, I have been cleaning up the petrol taps.

After several sessions in a hot ultrasonic bath, we have two clean Enots petrol taps, the type with the famous 'HexagON'. One is a reserve tap in that it has an additional reserve lever - so the bike will have three options - one side of the tank through one tap, the other side of the tank through the other tap, and a portion of fuel available from one side of the tank with the tap in the reserve position. How useful.

So, after ultrasound we have the Dremel & brass wire brush to buff up the nickel - which is has a distinct 'patina' brought on through years of service and inappropriate spanners. Nothing to stop them working though, at least, nothing that a new set of seals won't cure.

So, rummage around under the bench for the remains of a 1/4" thick cork table mat, and we can set about making some new ones:

• make a wad punch out of some 15 mm tube, sharpened at one end
• whack the punch into the cork with a mallet, onto a stout hardwood anvil
• realise this only crushes the cork
• think again and resharpen the punch
• screw it into the cork to actually cut the seal blank out
• do it five more times
• stick a dowel inside the tube and push out your six blank seals

having crawled around the workshop floor, since they shot out of the punch and went everywhere, go and have a cup of tea. Next:

• punch a small (4mm or so) hole in the centre of each blank
• thread each seal onto a suitable screw, retain with a nut & washer
• chuck the screw in an electric drill, or a lathe if you are lucky
• using a 60 grit sanding pad, followed by 120 grit, reduce the seals to 1/2" diameter in your makeshift lathe
• strip it all down and admire your handywork.

Next, oil the seals and wait a little while. Now you can put them in the taps, reassemble and revel in the fact that you have saved yourself £3.50!