1951 BSA A7

[anjimehra]

Hi

Happy Hew Year to all.

Anybody know the size & no of the engine oil seal ? The bike came as a basket case missing a few parts. Thanks
Anji

[muskrat]

G'day Anji. The '51 AA7 didn't have one. they were used from '53 I think in the BA7's.
Cheers

[anjimehra]

G'day Anji. The '51 AA7 didn't have one. they were used from '53 I think in the BA7's.
Cheers

Thanks muskrat. That makes life alittle easier. Any idea where I can free download a w/s manual for 1951 A 7 ?

[muskrat]

G'day Anji.
Wiki has a good list of pages to view, you have to join Wiki to download. I just copy and paste into Word.
http://www.bsawiki.co.uk/index.php?title=Chapter_list
Cheers

[anjimehra]

G'day Anji.
Wiki has a good list of pages to view, you have to join Wiki to download. I just copy and paste into Word.
http://www.bsawiki.co.uk/index.php?title=Chapter_list
Cheers

Thanks muskrat. Much obliged
Anji

[anjimehra]

Hi

Does anyone have an exploded view of the 1951 AA7 engine ? Logic says that there must be a bush with collar on the timing side, but this one docent . It has plain bush but thecae itself has a step cast in where the bush sits ( hope that makes sense??).
Anji

[bsa-bill]

Hi Anji

not quite sure if I've got this right but if your talking about the timingside bush it does have a collar but the collar goes to the inside of the crankcase so nothing to be seen from the outside except the plain end of the bush.

[muskrat]

G'day Anji.
Hope these help.
Cheers

[anjimehra]

G'day Anji.
Hope these help.
Cheers

Thanks Muskrat & Bill

Attaching some photos of the timing side crankcase. Cant see any scope for a flanged bush !! as the crank wont fit inside the cases.
Whats your take on this ?
Anji

[muskrat]

Yep that's the bush. It's the type that has a steel outer and bronze inner. See how it fits between the two flats in the casing. Do not try to press the bronze bush out as they are sometimes pegged to the outer. To remove just heat the case to about 200 C and it will fall out.
While your there. Behind that screw is the oil retaining ball & spring (anti wet sump valve). Replace them
Cheers

[bsa-bill]

yep thats just as Muskrat states, the bush in my post is the other type used (solid brass/Phosfer bronze) so looks quite different to the one in your case - should of mentioned that

[trevinoz]

And reseat the ball!

[muskrat]

Good point I missed Trev. I buy two balls . I use one new one to tap onto the seat and trow it away and use the other new one.
Cheers

[Marqs1979]

Good point I missed Trev. I buy two balls . I use one new one to tap onto the seat and trow it away and use the other new one.
Cheers

I tested this as I have read about on this forum. Glued ball on a rod and used valve grinding compound.

[chaterlea25]

HI All,
Be extremely careful when reseating the ball valves 
I would not grind in one in
The more the seating is hammered / punched / ground the wider the seating becomes
this lowers the spring pressure per sq mm and leads to leakage past the ball 

HTH
John