Author Topic: BSA A10 Breather Replacement - Advise  (Read 732 times)

Offline ALPH1

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Re: BSA A10 Breather Replacement - Advise
« Reply #15 on: 17.09. 2019 19:26 »
WOW thanks John,, I should have been reading this while spinning that thing over and over *smile* I was sure is was never going to line up again. Yeah thats the issue with discovery as you go.. You only know youve made a mistake after you have done up but hey, this morning I didnt know what was under the cover and now I do thanks to all the help. The cork washer does have to much play so it needed dismantlement anyway and the fear has left!



Offline ALPH1

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Re: BSA A10 Breather Replacement - Advise
« Reply #16 on: 17.09. 2019 19:52 »
WOW thanks John,, I should have been reading this while spinning that thing over and over *smile* I was sure is was never going to line up again. Yeah thats the issue with discovery as you go.. You only know youve made a mistake after you have done up but hey, this morning I didnt know what was under the cover and now I do thanks to all the help. The cork washer does have to much play so it needed dismantlement anyway and the fear has left!






Online Greybeard

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Re: BSA A10 Breather Replacement - Advise
« Reply #17 on: 17.09. 2019 19:56 »
I think you have it timed ok by those photos  *smile*

Offline ALPH1

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Re: BSA A10 Breather Replacement - Advise
« Reply #18 on: 17.09. 2019 20:00 »
Yeah thanks Greybeard! Id do it again now *smile*

john, you based in Ireland.. Myself included.

Al


Offline duTch

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Re: BSA A10 Breather Replacement - Advise
« Reply #19 on: 17.09. 2019 20:17 »

 Hiya Alphi- as John stated and regarding previous ideas, for future reference, and if nothing moved while the idler is unmeshed, the process can be shortened somewhat by simply rotating it all just enough-should be no more than two crank revolutions- to have the marks on the **camshaft and crank pinions** in the correct orientation (without needing the idler marks anywhere near), then just pull the idler out and re-align the marks to check if it's correct.....as John suggests I think I read somewhere the magic number of rotations between alignments is 97, but that's from the back row of my neurons *eek*.

 As discussed in another recent thread, some of us use a gasket paper shim the right thickness behind the cork to pack it out...(also taking into account the cover gasket thickness)
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Offline muskrat

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Re: BSA A10 Breather Replacement - Advise
« Reply #20 on: 17.09. 2019 20:58 »
G'day Alph.
Good to see you got a handle on this now. I'd replace the dynamo cork as well. That compartment has grease for the chain.
Now get over to introductions and tell us your story.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
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Offline chaterlea25

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Re: BSA A10 Breather Replacement - Advise
« Reply #21 on: 17.09. 2019 22:42 »
Hi Al,
Yup, In the Peoples Republic of Cork

While you have the covers off check for vertical and in out movement on the crank end
1 1/2 thou vertical and a max of 3 thou in out

John
1961 Super Rocket
1963 RGS (ongoing)

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Re: BSA A10 Breather Replacement - Advise
« Reply #22 on: 18.09. 2019 08:43 »
Al, As a precaution I would remove the sump plate and clean the filter gauze, also check the little ball valve is free to move. Remove the oil tank and oil lines, clean and blow through. Be careful to reconnect the pipes correctly, the crankcase is marked F...Flow and R ....Return. Refill with the correct recommended quantity of fresh oil. Reading your first post would indicate to me that the scavenge side of the oil system is not working properly, or that the system is overfull. The first sign of this is a smoky exhaust, and oil being dumped through the breather. When running, the oil level in the tank should stay the same, or even rise slightly as the pump returns oil which accumulates in the engine sump. As mentioned, the dynamo chain is tensioned by slackening the dynamo strap and rotating the body. Pull the dynamo towards you to trap the cork sealing washer between the inner timing cover and dynamo, replace the grease as this is the only lubrication the chain gets.


Swarfy.

Offline ALPH1

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Re: BSA A10 Breather Replacement - Advise
« Reply #23 on: 18.09. 2019 09:33 »
Thanks Swarfy, John, Mustrat, duTch for all the great advise!

Swarfty --good sleuthing and think you have a very good point.
I may have been overly generous with cheap gasket seal due to the rocker cover oil leak and I was thinking some oil passage had become blocked and was contributing to or causing this issue. The oil was returning but did drop in level as it was loosing oil from the breather. The I topped it up a little.

So check list:
remove sump plate clean filter
I had the ball valve out but I'll check that again
place oil - verify quantity.. Was sure I had this right at 4 1/4 pints. will double check that for sure!
Blow out lines flow and return. I tipped this blue and red dots as never noted the marks before
Remove oil tank and clean all lines and filters.
Replace grease 1/2 LB is If im right.

Thanks Guys!

AL

   

   

Online Swarfcut

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Re: BSA A10 Breather Replacement - Advise
« Reply #24 on: 18.09. 2019 13:53 »
Grease to reach about halfway up the big sprocket....that's plenty.

Offline ALPH1

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Re: BSA A10 Breather Replacement - Advise
« Reply #25 on: 18.09. 2019 15:41 »
all back in and turning over OK. no jamming up and seems smooth now on to cleaning all the oil pipes.

John.. Could not find any play on the shaft. This normal?

Thanks
Al

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Re: BSA A10 Breather Replacement - Advise
« Reply #26 on: 18.09. 2019 16:07 »
The ball valve on the scavenge pipe in the sump is fixed, so if we are talking about the same valve, the pipe  should be firmly sealed into the crankcase drilling. A leak here means the pump will suck air instead of oil. The ball should be free to move, and the valve should not be able to be removed.

The figures quoted by Chaterlea John are a sort of ball park figure for a well used engine. Any less is a good sign. Looks as if you have no appreciable play with a cold engine, so that is a reasonably good motor.

Offline chaterlea25

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Re: BSA A10 Breather Replacement - Advise
« Reply #27 on: 18.09. 2019 16:22 »
Hi Al,
Quote
John.. Could not find any play on the shaft. This normal?
*smile* *smile* *smile* Great

Quote
The figures quoted by Chaterlea John are a sort of ball park figure for a well used engine. Any less is a good sign. Looks as if you have no appreciable play with a cold engine, so that is a reasonably good motor.

+1

That never happens to me, Everything that arrives here is shagged out  *problem* *problem* *problem*
(or seized) *sad2*

The new breather cork should be under a little compression when fitted, I have found new corks can shrink after some use and the breather goes slack
Too tight and the sleeve wears the timing case


John
1961 Super Rocket
1963 RGS (ongoing)

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Re: BSA A10 Breather Replacement - Advise
« Reply #28 on: 18.09. 2019 16:23 »
The ball valve on the scavenge pipe in the sump is fixed, so if we are talking about the same valve, the pipe  should be firmly sealed into the crankcase drilling. A leak here means the pump will suck air instead of oil. The ball should be free to move, and the valve should not be able to be removed.


Yes, this did worry me!
Quote
I had the ball valve out but I'll check that again


Offline ALPH1

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Re: BSA A10 Breather Replacement - Advise
« Reply #29 on: 18.09. 2019 18:12 »
Oh! so what I was taking about was the pressure release valve :) double nut,spring and small bearing to the front of the case.

Thanks

Al