Rubber missing in points

[oval57]

What effect does it have on the running of the bike (52 A10 ) if the little rubber block is missing that goes under the spring arm on the points ?

[JulianS]

Will run OK as both the spring and the moving contact are earthed to body, but the spring could slide off or wear so best if the little nylon nipple is in place. Modern pattern points and genuine lucas come with the little button, the Lucas one being pressed in and smaller diameter than the pattern item.

[Triton Thrasher]

You must be able to carve a piece of dowel or something, to fit.

[oval57]

Not sure if this was causing the problems I am having, riding around town the bike performs well on the highway I go about 5 kms at 55 / 60 mph and the bike starts loosing speed drop it back to 3rd away it goes as if nothing wrong, back into top and it starts to die drop back and all OK for a kilometre and it starts to die . Checked the plugs after the fast ride they are a dark tan colour. Bike has only done about 100 miles since rebuild. Any thoughts  and I have cut a small section of an o ring and made a replacement button between points and spring clip

[Greybeard]

Was the magneto overhauled?

[orabanda]

Try a new set of plugs

[JulianS]

Check lubrication if engine feels like it is dying. Thereare some really nasty oil pump to crankcase gaskets being sold which severly restrict oil flow.

Photo shows on left an SRM gasket complete with extension for third stud, top right a new old stock BSA original and bottom right the nasty pattern item. With the latter note the smaller oil holes and also the larger mounting holes (for the dowls used on untit singles) which can allow the gasket to displace on assembly and further restrict oil flow.

[Triton Thrasher]

As well as those rather vital oil supply matters, check the petrol tank cap vent hole is clear.  Also all the gauzes in taps and carburettor.

Take the bung out of the bottom of the carb and see if about 400 ml can flow through in a minute.

[Triton Thrasher]

Oh- and have you messed around with sprocket sizes and overgeared the bike?

[oval57]

I have tried new plugs, the originals were only just put in when the rebuild took place.
Yes the Mag has been rebuilt
No I have not played with sprockets.
Could be fuel, I accidentally filled the tank with 85 and story is that it can destroy tank liners
I will change fuel caps tomorrow and try that
Thanks guys for all the suggestions, fingers crossed its something simple !

[Triton Thrasher]

You should be able to blow into the tank through the little hole in the cap.

Or just loosen the cap while riding, when the symptoms show.

If your tank is lined, that’s a bit suspicious.

[oval57]

Thanks guys for all the input, what started as a bit of rubber missing in the points turned into a lot more of a concern. The bike kept slowing almost like a siezure but it didn't quite feel like it, had me stumped tried almost everything, one thing at a time, kept doing the possible siezure bit, dropped a scope in the bore, all good.... Anyway as it turned out the valve clearance had closed up, reset the tappets.....happy days, first run out 30 miles sweet.....going for a big ride today if the weather holds out......cheers

[Triton Thrasher]

When you retighten the head and barrel, you have to check the clearances.