Author Topic: Primary chain case  (Read 352 times)

Offline TT John

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Primary chain case
« on: 26.04. 2019 11:01 »
Oh what fun I have had today, I had to remove the inner chain case on the A7 as it was leaking pretty badly, after removing and cleaning, I checked where the leak had been coming from, suspected an old repair that had occurred earlier in its life, so went over that with some low melting point alloy wire I had bought previously but while doing that it showed up another crack near a screw hole so, same procedure, heated up chain case and did that, I am now hoping that I have an oil tight chain case, it its okay I will be using the A7 for the John Bull rally on the 3rd.
I had been putting off repairing this chain case for some time but there comes a time when you just have to say sod it and get it sorted, I think half the time its a question of do I really want to do that but you have to do it in the end and get some satisfaction.

TTJohn

Offline LJ.

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Re: Primary chain case
« Reply #1 on: 29.04. 2019 10:02 »
Allo John, pleased to hear your still having fun with the old BSA!....

Likewise only last week I did a similar job but on the inner timing case, had fun trying to take off the taper dynamo drive sprocket. Job sorted in the end and is much better, might have saved myself some hassle if I put in straight 50 oil as opposed to 20/50 which is a lot thinner. Other A10 has the straight 50 and doe's not leak as badly.

Love to Gill, hope she is keeping okay.
Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Offline Rocket Racer

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Re: Primary chain case
« Reply #2 on: 30.04. 2019 06:01 »
most every preunit twin inner chain case I've ever seen has been as straight and true as a banana.
put one on  piece of glass and just look at the bowing on both sides...
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
New Zealand

Offline TT John

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Re: Primary chain case
« Reply #3 on: 30.04. 2019 10:27 »
LJ, Yes still doing a bit mate, I managed to used some low melting point alloy and once off and heated up showed up another crack, which I attended to at the same time, that is now leak free but I still have one leak coming from somewhere else, looks a bit like the crank case joint. Yes, Gillian & I are both fine, she is still working keeping me in a style which I have come accustomed to, I trust & hope Alison & the family are all okay.

BB, The primary chain case is quite good and true but I find that some folk tend to try and tighten them too much, which pulls the thread and so causes a raised part around the screw hole but BSA's are noted for their leaks and I'm yet to see one that doesn't although, I am doing my best to get it oil tight, I think the main cause of my problem is having too many bikes, not putting all effort into just one or two.

Regards TTJohn

Offline Rocket Racer

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Re: Primary chain case
« Reply #4 on: 30.04. 2019 21:36 »
, I think the main cause of my problem is having too many bikes, not putting all effort into just one or two.

Regards TTJohn

the first world problems we suffer from  *whistle*
I keep saying I'm going to sell a couple of the newer ones (unit construction), but not sure even I believe it even though I dont really have the time or space to do them all justice...
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
New Zealand