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BSA B50MX "AIR BOX" - Is there such a thing?

Posted: Mon Apr 08, 2019 2:50 pm
by JAI
Hello all,

I'm completely new to the world of BSA. I recently purchased a B50MX motor in a TR5MX frame and was surprised to see the lack of air box or protection for the air filter.

I will be using the bike for flat track racing which due to track conditions, quickly fouls up an oiled filter that is not housed in an air "box".

Before I break out the cardboard, scissors and go all Blue Peter, does anyone know if an air box is available for purchase?

cheers,

John

Re: BSA B50MX "AIR BOX" - Is there such a thing?

Posted: Mon Apr 08, 2019 4:28 pm
by minetymenace
<135 to the forum JAI.

Would you update your profile and let everyone know roughly where in the world you are please?

If you press the "Spareparts" button at the top of the page, then go search by illustration, the select B50 1973 then "Air Filter......" you get here then select Item 3 from the drop down, you get:
Collected part: 83-3299
Description: Air filter assembly
Year: 1971-1973
Model: B50 MX

Some available in the US

Similar search method for road going versions which crop up on ebay all the time (eg search for ebay item number 311461347178)

Re: BSA B50MX "AIR BOX" - Is there such a thing?

Posted: Mon Apr 08, 2019 4:56 pm
by JAI
Hello MinetyMenace,

Thanks ever so much for the reply. I'm still finding my way around the site and the "Spare Parts" box is crossed out on my home bar however, it worked though!

Are the air boxes interchangeable do you know? So, for example, would 83-2042 (1971 B50T) fit my TR5MX frame or is it just compatible with 83-3299.

Thanks again; very much appreciated.

Jai

Re: BSA B50MX "AIR BOX" - Is there such a thing?

Posted: Mon Apr 08, 2019 9:22 pm
by minetymenace
Sorry JAI, don't know the MX too well, but it looks like different mountings to me, someone will be along shortly with an answer I'm sure...How about a picture?

Re: BSA B50MX "AIR BOX" - Is there such a thing?

Posted: Tue Apr 09, 2019 8:53 am
by beesa71
My two penneth; the BSA/Triumph OIF Single air filter housing is not what the OP needs if he is considering an 'air box' for Flat Track racing. It is, simply, a unit to hold the simple paper based air filter in the right place.

I have friends who race FT here in the UK and they need to construct multi layer air filtration units to address the issue of a dusty dry track.

I'd personally set about making up an air filtration unit to fit in/around the confines of the carb area and forget anything OEM.

The modern concept of an 'air box' where it does all sorts to aid flow/quieten the inlet noise isn't what BSA/Triumph achieved with either the B50SS/T unit or the similar one for the B50MX.

In about 1974 Can-Am, with their Rotax engined two stroke machines did produce an air box that had internal pieces that were intended to alter flow/reduce inlet roar and located on top of that air box was an oil impregnated filter. They (on our bikes, www.militarycan-am.co.uk) sound great without the air box...... real fast stood still!

Regards to all OIF'ers.

Paul.

Re: BSA B50MX "AIR BOX" - Is there such a thing?

Posted: Wed Apr 10, 2019 11:05 am
by JAI
Thanks chaps.

I've had a good look at both versions of the air filter set up and agree a paper filter is unlikely to be good enough although the MX item "minety" pointed me towards could probably be adapted to take a modern foam element. Nevertheless, with time pressing I think I'll stick with the foam tube behind the fibreglass panels for now but change the element after each heat.

I think it's cardboard, scissors & selotape time!

thanks again.

Jai

Re: BSA B50MX "AIR BOX" - Is there such a thing?

Posted: Wed Apr 10, 2019 12:29 pm
by minetymenace
A thought, PES make scrambley type things, and they do a V shaped GRP air filter box (that takes a foam filter) that goes where the battery and air filter goes on a propper bike( :oops: ) maybe it will pop straight into your MX frame?

Re: BSA B50MX "AIR BOX" - Is there such a thing?

Posted: Wed Apr 10, 2019 2:01 pm
by JAI
That's a great suggestion; I've sent them an email (and stowed the cardboard, scissors and glue for a minute :ban )