A10 1955 Airbox Wanted

[Stu55Flash]

Anyone know where I can get one of these from or alternative a drawing that I could produce one from?

Thanks

[terryk]

These airfilter boxes for plunger A10s are a bit rare to find these days but they do show up on ebay from time to time. There are two types you need one with the oval hole. I think there was earlier posts about these with pics. These airboxes include the battery carrier. They aren't reproduced as far as I know I have never seen them and I have been watching for them for years on ebay. Unfortunately those that have them for sale know that they are hard to find now and charge like a wounded bull.
Just be patient though one will show up keep watching ebay around the world you may even have to buy parts because different bits show up here and there as well.
If you want to ride the bike now and are concerned with an airfilter put another type of carby on it like a concentric with a small screen type filter until you find the original airbox. I have been riding daily to work etc on a 1949 B31 BSA with no filter at all but always avoid really dusty roads. I have had the head and barrel off it recently to check what I found to be a bigend noise. The bore and piston are still very good even after years of hard riding etc so it doesnt seem to worry it not having an airfilter. You just have to make sure nothing big goes near the carb so a screen would be good.
I tried a screen on the B31 once it didnt like it and kept dyin in the bum it seems to want to breath fresh air. The BSA manual doesnt give a jet size for carby without a filter which would be a smaller size. I could have tried a few but I just didnt worry about it thats how they were anyway on some bikes.

[Josh Cox]

Hi Stu,

I have a 53 plunger, I cut the air filter unit off the bracket and fit a bellmouth ( also have 376 carb fitted ), looks great, also have a spare complete and repaired housing, photos below.

[trevinoz]

Terry,
               I am curious as to when the airbox was changed from the central hole outlet to the oval side hole outlet.
Do you know?
I was thinking maybe 1949 when the A10 was introduced.
     Trev.

[Brian]

The 48' parts book shows the central hole type (67-4535) and the 49' onwards book shows the side hole type (67-4594).

My 51' A7 has the central type however which may throw a spanner in the works but of course it could be wrong. It was fitted to the bike when the previous owner bought it and would appear to be original but as always could well be wrong.

Here's a pic of the bike in its "before" condition, looks unmolested but who knows.

[Josh Cox]

Trev,

I am under the impression that the air filter changed when they went away from the type 6, mine should have a type 6 (276).

With all the 376 equipped bikes I've seen, they have the round type filter.

[terryk]

I have wondered that to Trev. I first thought that all the long strokes had the earlier airbox but as Brian says the part list says different. I have a 1948 A7 and yes I am still chasin that enclosed front engine mount please keep your eyes open for me at your swaps.
I also now have enough bits and pieces  to build a 1950 longstroke in a plunger so I will find out when I get to it if the longstroke with original carby lines up ok with the later airbox cant see why not. You wouldnt believe it but I have the rubber that goes between the first type airbox and the carb ( they are almost non existant).

[trevinoz]

Josh,
          I think that the plunger bikes used the type 276 until the end of production. I will check my Amal book later.

Now all of you knowledgeable blokes, what air/battery box was fitted to the '49/'50 Star Twin?
Obviously they don't need an air filter so did BSA make a special battery box for this model?
I have both types as above on the shelf but don't know what to use on the Star Twin. Maybe I should shout myself a parts book for this one.
   Trev.

[Brian]

Here's a scan out of the parts book Trev, the one in the bottom right corner is the one listed for a Star Twin (67-4576).

When I did my bike I had a look at it and as far as I can see it is exactly the same as a normal one with the air filter box missing.

If you have one with a damaged air box that you can cut off then I am sure that would be right.

[trevinoz]

Thanks, Brian.
                         Mate, the scan didn't post. Will you have another go please?
Trev.

[Brian]

Bugger, try again. I've attatched it to the first reply. (hopefully)

[trevinoz]

Thanks, Mate.
Trev.

[terryk]

I have one of these battery carriers how do I put pics on here I havent looked at how to do that yet.

[bsa- bill]

Type what you want in the reply box, then at the bottom left corner you will see "Attach" click on the "Browse" tab to select your picture file from wherever you have it stored, click open or double click on the file and the file name should appear in the box to the right of Attach.

All the best - Bill

[Stu55Flash]

Any chance someone could scan in a drawing with dimensions on? This would be a big help.

Thx

[trevinoz]

Terry,
                If that battery carrier is surplus to requirements, I am interested in it. It would save butchering a good airbox.
              Trev.

[terryk]

Gday Trev, no I am hangin onto that battery carrier I have a star twin manifold as well so I may make a longstroke star twin down the track. I can send it down if you wanna to copy it though. cheers Terry

[trevinoz]

Thanks for the offer, Terry, but I have a few airboxes so I will just cut one like Josh did.
There's no hurry to do it as the Star Twin is a long way in the future.
Trev.