Sliding Primary Plate with Oil Seal..where to get?

[ironhead]

The state of the roads bounces the oil fairly violently. Then the chain throws it about. Have fitted the SRM felt seal Which has squeezed The clutch chainwheel slightly out of line with the engine sprocket.  Will run it tomorrow anyway but is there a spacer/ washer that fits behind the front sprocket or will i need to have something made up?

I think you will find the clutch sprocket will easily overcome the push from the felt. Should be nicely run in after a few miles.

[Peter Gee]

Hello Big Jim, the felt will bed in quickly IMO on it's own..it's highly compressible, more so than for example cork.

[Peter Gee]

You could fill it until oil runs from the level screw.

Thanks Trevinoz..I have a slight  bitsa situation on my primary side... a later (post 60?) chaincase with the level plug...which I had to blank off with a grubscrew because new pipes don't from UK supplier don't  fit otherwise..I think Ill drain it with a fork suction syringe I have from USA for levelling my dirtbike forks.

[bikerbob]

I never use the level screws for either the primary or the gearbox because what is level, is it with the front wheel touching the ground or the rear wheel and my garage floor is on a slight slope as well.  So i always measure the correct amount out and every couple of years I drain both and refill with new oil. If you have put in more than twice the recommended amount  then you are going to have some really large amounts of oil leaking out of the rear of the primary, and maybe clutch slip, 8 fluid ounces or 225cc not 236cc is the correct amount for the primary.

[Peter Gee]

Thanks Biker Bob for this clarification, so the Hayne's liar's manual was right for once!! 225 it is.

[BigJim]

Sorry Peter Gee to hijack your thread. So have given the primary a good run and felt seems to be working. Oil is however issueing strongly from the sliding plate holding bolts. These are the shouldered type, although one has a shoulder pretty worn out. Will order replacements but the inner primary case has enlarged holes and i imagine they will leak anyway. Thinking a tight fibre washer on outside? The ideal would be to drill and bush the holes? Any suggestions appreciated. Obviously RD i could run it dry but will worry about how hot the chain and clutch may get?

[Peter Gee]

Sorry Peter Gee to hijack your thread. So have given the primary a good run and felt seems to be working. Oil is however issueing strongly from the sliding plate holding bolts. These are the shouldered type, although one has a shoulder pretty worn out. Will order replacements but the inner primary case has enlarged holes and i imagine they will leak anyway. Thinking a tight fibre washer on outside? The ideal would be to drill and bush the holes? Any suggestions appreciated. Obviously RD i could run it dry but will worry about how hot the chain and clutch may get?

The ideal might be to helicoil or brass bush the holes that are enlarged. If the holes are enlarged they will leak anyway, and fibre washers, esp with Threebond on the mating side allowed to suitably harden-off ( 24 hours+ as it NEVER gets totally hard) might  work. I'd also try thread-taping the bolt threads copiously as a first try.

[ellis]

SRM recommend no more than 190cc in the chain case of engine oil.

ELLIS

[Greybeard]

SRM recommend no more than 190cc in the chain case of engine oil.

On all 'A' models?

[berger]

"on all A models" possibly to stop their super clutch slipping ------------joke!

[bikerbob]

Why does SRM advise only 190cc as opposed to 225cc.  According to Roy Bacon's book on BSA twins the primary case capacities are listed as
1947-51 284cc or 0.5 pint
1952-53 90cc or 0.17 pint
1954-57  Plunger models 115cc or0.2 pint
1954-63  s/a models 225cc or 0.4 pint
1962-72 Unit models142cc or 0.25 pint

[Peter Gee]

Can't figure out why my post has gone practically viral...I wish the one asking for Kisck Start cast Iron bush measurements was ditto......

[RDfella]

I noticed that, but don’t fully understand the query – assuming I’ve remembered the post correctly. Why exactly do you need measurements? The bush OD will be an interference fit in the case (which you have) possibly .0015” to .002” given it’s steel into an alloy case, and the ID will be around .001” over the quadrant (which you have) OD. I’ve only a rigid singles bush to measure, and I don’t think they’re the same as the A series.

[Peter Gee]

The dimensions to give the turner at the machine shop!  I will reword my post above!

[RDfella]

Git it now - though you had the box in bits so couldn't understand why you needed someone to tell you the size.