As the piccies shows, the brackets on my front mudguard are both spot welded and brazed into position. (The dull custard coloured splodges is bright brass in colour when scratched.)

I've drilled out the spot welds. Now I need a way of getting the brazed joints separated. I'm guessing the brass filler will melt again if suitably heated. Would I be able to get it to temperature with a plumber's blowtorch? Or do I need someone with oxy acetylene?

 

Thanks for the steer Rupert. I took the cover back off and checked the oil seal.  I had ordered two seals: camshaft points and the clutch cover one.  The camshaft points one is correct. But the other seal is an imperial one marked 1.187 - 0.750 - 0.250.

This translates to 31.75, 19.05, 6.35
My research shows that 30.3, 20.6, 6.3 is the normal sizing for 40-0243. I think that explains why it was tricky to fit into the plate, and too tight on the sleeve gear.

The old seal (retrieved from the bin) was marked 70-3833 which is the same as 40-0243. The larger id is obvious.

Since refitting the gearbox seal cover plate into the back of the chaincase, with a new seal and new felt ring, it is very hard to spin the sleeve gear. I had expected the seal to slip over the mainshaft, but the sleeve gear comes through it. Is that normal? Also the felt ring is clearly being compressed to half its width or less - again, is that normal?

I find that modern fibre washers are useless. I generally fit a dowty washer instead.

Thanks for that.

On getting a replacement seal, what I really meant to ask was, is there a recommended brand. I note that most dealers are flogging Wassel seals. But should I be paying the extra for SKF or something like that?

In another belated move, I have decided that trusting the 60 year old oil seal on the C15 drive side is daft. But is it possibe to get it out, with the crankshaft in situ?  And if so, how?   Now that the worm drive, oil pump, sump etc are fitted on the timing side, I really don't want to split the cases again....

Second part to the question - does anyone know of a source of good oil seals? I've had several fork oil seals for other bikes recently that were useless - just like modern fibre washers.

The circular gearbox sprocket cover plate / oil seal holder in the back of the primary chaincase has a small protrusion on the external face. Does the cover have to be fitted in a specific orientation so that the protrusion performs whatever its purpose is - perhaps related to the chainguard?

Also - I have fitted the oil seal into the cover with the open side facing into the chaincase. But in the Rupert Ratio book pg 118 it looks as though the seal is the other way around (but that might be a trick of the light).

Its off!  Heat seemed to be the key factor. Thanks for the ideas!

I've belatedly decided to renew the oil seal in the primary drive that seals the sleeve gear. I've removed the six screws - and can't get the cover plate to budge. There are traces of some black compound on the gasket fitted by the previous owner - I assumed it was RTV but am now wondering if it is a glue!

I've tried brushing a drop of acetone around the edge, with zero effect.

Does anyone have an clever ideas for shifting it - other tham hammers and chisels!

Due to wear at the bush end, I am replacing the layshaft on my C15F. I managed to find a NOS shaft. The Service sheets explain that the innermost cog is a press fit, which also retains the next cog (and the thrust washer I believe). So I need to get this 'pressed' cog off along with its neighbour and the thrust washer, and fit them to the new shaft by pressing on the end one.

Does anyone have any experience of doing this?  I have various pullers but they won't fit into the gap between the first and second cog. At the moment my thoughts are that I will need a length of 1 3/4" pipe, to fit over the shaft and bear on the second cog, so that this presses on the first cog, and then I can put this in the vice and press on the shaft end, to liberate the first cog etc.  And then for reassembly I can just use a long socket over the layshaft bush end of the shaft to press directly on the small cog and press it home.

Will this work? Will heat help?

You might want to read this thread in twins. https://www.bsaownersclub.co.uk/bsaoc_forum/index.php?topic=15065.msg81323#msg81323

I'm pretty sure I have read about two different cup sizes - probably in one of the Rupert Ratio books.

Has anyone got a tried and tested method of dealing with rust between the spot welded bracket and the muguard? My C15 has bulges in the front mudguard caused by rust expanding underneath, between the mudguard and the braket. And on the rear mudguard, the brackets are distorted by the expanding rust to the extent that one has broken loose at one side. I had thought that after dousing them in evaporust etc the problem was dealt with, but clearly six months later the rust is still growing.
The attached picture shows the distorted and partially liberated bracket after I had removed most of the rust build up. But I don't think I can get behind most of the other brackets.

Does anyone know of a mod or an easier to use version of the centre stand for the A50 / A65 bikes pre oil in frame? My 1968 Royal Star is getting harder for me to get onto its main stand. I also have a BMW R80 which has a wonderfully engineered stand that requires a fraction of the effort - and I read about someone producing Matchless stands that are similarly low-effort. Is there such a thing for my BSA?

Going back to Dave Brady's point, and your reply 'yes it has a Choke fitted in the carb,this was reconnected to the lever that turns back and forth as used on the handle bars, and that seems OK,'.

The BSA choke lever works in the opposite sense to bikes such as BMW's.  I'd suggest you take the rubber air inlet tube off the carburettor so that you can see (or feel) the position of the choke slide. With the throttle twist grip held wide open, and the choke lever set to 'off', the only obstruction in the carburettor should be the needle. Then look again with the choke lever in the opposite position.  Your symptoms are exactly those you would get if operating the choke in the reverse sense....

Hi

I need to remove a Lucas K2F magneto from a bike. The magneto is fitted with the automatic advance/retard assembly on the big fibre timing gear. I have got conflicting information as to whether the securing bolt is normal right hand thread or left hand thread. Can anyone confirm?