The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: Peter Gee on 28.08. 2019 20:29
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Chaterlea has mentioned one can get a sliding plate with a proper oil seal, to cure the felt seal leak.
Who sells, kindly? Mine is like Niagra Falls back behind the chaincase on ATF, with the new felt seal. I don't think 20 SAE would help.
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Need help with mine so am following with interest.
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Chaterlea has mentioned one can get a sliding plate with a proper oil seal, to cure the felt seal leak.
Who sells, kindly? Mine is like Niagra Falls back behind the chaincase on ATF, with the new felt seal. I don't think 20 SAE would help.
Read this thread, there are cures for oil leaks mentioned. - https://www.a7a10.net/forum/index.php?topic=14519.msg121022#msg121022
I did away with my felt seal.
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I got mine from Baxter Cycle in the US
It was made in the UK and appeared to be well made
S
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I have modified an existing sliding plate as per photos but the side with the brass plate attached is too high so I intend this winter to have another go at it.Had a look at the one for sale at Baxters in the USA looks well made but not sure if I might have the same problem with the height.
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None of my primary cases leak. Maybe because I stopped putting oil in primary cases over 40 years ago.
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Don't overlook the engine to primary case join.
I was recently breaking my head about a pool of oil underneath the primary case every time I parked the bike. *conf2*
Convinced that it came from the sliding plate, I added a felt seal between clutch chainwheel and sliding plate but it kept on dripping out until it dawned to me that the oil came from further up front and the riding wind blew the oil backwards. When parked it then dripped down like it came from the sliding plate...
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The simple way is to put a smaller felt seal on the reverse of the clutch centre which seals the gap and, as I have found over a number of years is very effective. A lot cheaper too. Most oil leaks fron the gap between sliding plate and the centre and the scroll does not do much
Comes with the SRM 4 spring clutch kit but also available on its own.
http://shop.srmclassicbikes.com/product/felt-washer-centre-adaptor-4-spring-clutch-centre
Dont know if it fits 6 spring.
Gold Star man Dave Flintoff also does a sliding plate with seal
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Will try the srm felt seal.
Have been ringing that phone nr for some tim e with no answere. Will try an email.
Thanks Julian
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One thing for all those posting on here about using almost no oil, or squirting a little on every now and then to the primary chain....how on earth does the clutch bearing get lubrication in that case?????
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G'day Peter.
As long as the chain just touches the oil it will be flung around enough for a little to reach the bearing.
When racing my A7SS with an open (dry) primary (4 spring chain driven clutch) I'd give the chain a squirt before each race. Re-pack bearing after every meeting (6-10 races).
In the A7 plunger I use the recommended amount of oil but quite often there's more in there due to motor wet sumping (no crank oil seal).
Cheers
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Thanks Musky and many others...ok so I put the Haynes recommended amount of ATF/SAE 20 in the Chaincase..8 fluid ounces = 236 c.c. and the ATF was way below the level of the primary lower run. Had to basically double that figure to get it touching ( and a bit more) the chain.
Anyone have any more quantities than Haynes?
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You could fill it until oil runs from the level screw.
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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?
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.....ok so I put the Haynes recommended amount of ATF/SAE 20 in the Chaincase..8 fluid ounces = 236 c.c. and the ATF was way below the level of the primary lower run. Had to basically double that figure to get it touching ( and a bit more) the chain.......
Pete- If you looking into the inspection/add hole, you may be not allowing for the bottom of the cases not being level (the bulk of the oil is out of sight under the clutch)
....... 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?
Jim- There should be a spacer that runs in the seal between the bearing and sprocket - it's about 3/8" wide (Part#67-1138 ) and possibly shims P/n# 67-2056/7/8
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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.
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Hello Big Jim, the felt will bed in quickly IMO on it's own..it's highly compressible, more so than for example cork.
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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.
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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.
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Thanks Biker Bob for this clarification, so the Hayne's liar's manual was right for once!! 225 it is.
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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?
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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.
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SRM recommend no more than 190cc in the chain case of engine oil.
ELLIS
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SRM recommend no more than 190cc in the chain case of engine oil.
On all 'A' models?
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"on all A models" possibly to stop their super clutch slipping *fight* *whistle*------------joke! *shh*
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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
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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...... *smile*
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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.
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The dimensions to give the turner at the machine shop! I will reword my post above!
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Git it now - though you had the box in bits so couldn't understand why you needed someone to tell you the size.
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Git it now - though you had the box in bits so couldn't understand why you needed someone to tell you the size.
No RD fella I don't have it in bits, it's mounted and the bike was finished and run for a forthcoming competitive Africa International Show, when the KS prob showed up. Am trying to avoid any more stripdown than necessary by extracting the old inner KS bush with a pilot bush remover, but that is 10 days postage time from Europe away....meanwhile..... anyway, luckily Durch BSA Owners website has allthe specs I found out today.
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G'day Peter.
I think I have a bush buried in a box of bits. I'll look after work today.
Could you post a link to the Dutch BSAowners page where you found the info?
Cheers
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Sure Musky..here it is...incomplete like most BSA factory info...Gosh looking at my Triumph Workshop manuals, they just about list the diameter and specs of the wiring loom connectors! :-)
https://www.bsa-oc.com/en/service-sheets-2/
(https://www.bsa-oc.com/en/service-sheets-2/)