Sp250 carburettor jet replacement

[Martyn Ross]

Forgive my ignorance: I had a petrol leak and have traced it to one of the carbs. Carb removed and partially dismantled and it seems to be the rubber seal fitted to the jet has perished. So I have to purchase a new jet, which looks simple enough to fit but do I need a particular size - there are no ID marks on the failed item. And then do I need a new needle as well? I can't find a thread that deals with this - reassembly should, I guess, be simple.
The carburettor is marked AUC 7080W which is (I believe) an HD 6.

p.s. aren't the lower nuts (carb body to manifold) a b****r to get a spanner to!

Many thanks in advance

[classiclife]

Hello Martyn,

I have opened the relevant SU / Burlen (SP250 ) guide for you, which will provide all the technical info you require. Click on the appropriate VIEW and then scroll down for your shopping list !!

http://sucarb.co.uk/cf/vehicle/list/?ma ... art+SP+250

It is worth noting that the carburation spec for the SP250 and the V8 saloon are different - worth bearing in mind.

Burlen are very helpful and I'm sure they will see you right, on speaking with them.

Regards.

Richard.

[Ian Slade]

That is the diaphragm as in the D of HD as opposed to screw S in HS as fitted to MGB etc, part no. 6957 AUC.8155 item 266 on plate 6 page 14 of the SP 250 parts catalogue it is item 4 ln the Burlen catalogue as in Richard's link.

[Martyn Ross]

Richard and Ian

Thanks to both: I'd got the part on Burden's site but was unsure if it was correct. I havn't fiddled with carbs since the sixties so am more than a little rusty!

Martyn

[bobtills]

I'd speak to someone at Burlen.

I ordered a new fuel pump for my V8 from someone else and they sent the wrong one

I spoke to Burlen and they really knew their stuff- a new (right) one arrived very soon for near enough the same price as the wrong one.

[Kbeal]

You'll have to centre the jet with a new diaphragm, easy enough there are instructions on Burlen's website how to do this and a few useful videos on you tube, this one is for an HD8 but the principle is the same:
Kevin

[Martyn Ross]

Thanks also Bob & Kevin

Correct part ordered - I'm off sailing to the Scillies for a fortnight and with your help when I return it'll be easy. Apart, that is for the lower bolts on the carb/monifold.

Best

Martyn

[Christopher Storey]

I have no idea what the man with the HD8s is playing at in the youtube video , but I should pay no attention to him ! HD carburetters should need no jet centring , unlike the earlier H and HS types

[russcarpenter]

Actually you do have to centre the new main jets and also be careful that when you've centralised the jet that if you remove it put in the same way round, same place IE the name stamping in the place you set it. if you rotate it, it will most likely rub or jam the needle.

[Christopher Storey]

Well, I stand corrected after looking at my SU Workshop manual. However, I have never found it necessary when putting in new jets on HD8 to disturb the jet locking nut , and thereby alter the position of the jet bearing, and thus we have perhaps just been lucky !