Author Topic: Bolt function  (Read 709 times)

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Blackthou

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Bolt function
« on: 30 March, 2020, 21:09:08 »
Hi,

I have a 1960 C15 distributor model. I have removed the outer gearbox cover and replaced the clutch actuating arm - had to make most of the bits myself. Thankfully all silky smooth now and not the dog rough operation it was before.

That's an aside really. There is a bolt 3/16 diamerter x about 2/14 long directly inline with the base of the distributor, adjacent to another case securing one, almost in the centre at the top. It doesn't hold the outer cover on so is it some sort of gallery plug? Can't seem to find any info on it or its purpose. Is it BA or BSC as well please?


JulianS

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Re: Bolt function
« Reply #1 on: 30 March, 2020, 22:49:13 »
The distributor clamping screw?

Blackthou

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Re: Bolt function
« Reply #2 on: 31 March, 2020, 09:21:01 »
Thanks but no. The distributor is held by a clamp separately.

berniej

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Re: Bolt function
« Reply #3 on: 31 March, 2020, 09:53:44 »
Hi there, as Julian mentioned, that is the distributor clamping screw and needs to be loosened to allow rotation of the distributor body to set the ignition timing.
Do you have something else fitted by a P.O. maybe?

Cheers,
Bernie
'49 M21/B31 hybrid
'56 M21 combination
B40 Super Star
A50CC project

JulianS

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Re: Bolt function
« Reply #4 on: 31 March, 2020, 10:31:56 »
Like this service sheet.

Blackthou

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Re: Bolt function
« Reply #5 on: 31 March, 2020, 14:18:12 »
Thanks all. That's most helpful but please see attached picture.

JulianS

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Re: Bolt function
« Reply #6 on: 31 March, 2020, 15:10:51 »
That screw is not a BSA fixing, something done by a previous owner, the questioned hole is the one for the clamping screw which is accessible from the outer cover to allow you to adjust the timing  without dismantling, I have enlarged a bit from the service sheet so you can see the clamp. Some of the clamps were soft metal and overtightening would strip the thread and owners inprovised rather than replace the clamp.

This ebay item shows the clamp.

https://www.ebay.co.uk/itm/TRIUMPH-T20-BSA-C15-B40-DISTRIBUTOR-BODY-CLAMP-70-4099-Free-Uk-Postage/283829133980?epid=2093183822&hash=item421588e29c:g:3KMAAOSwubRXE
« Last Edit: 31 March, 2020, 15:12:39 by JulianS »

Blackthou

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Re: Bolt function
« Reply #7 on: 31 March, 2020, 16:36:09 »
Thank you very much Julian. Greatly appreciated.

It also makes sense as the screw that should clamp the distributor was held in with sealant. I reckon as you say, someone has stripped the thread and improvised. Must admit they've made a neat job of it as the gearbox cover is beautifully counter-bored. I reckon it nips down directly on the body as opposed to being in a clamp. Can the clamp be replaced easily or does the inner gearbox cover have to come off? Will the clamp do any harm if it's still in there but not secure?

The bike's had an Alpha bearing conversion too so maybe someone more adept did it as most of the parts look like they've been serviced with the wrong size spanners or screwdrivers, generally messing everything up. The picture you see is after I've cleaned and prepped it all. Overall the bike is pretty original and pretty good just poorly fettled.