Looking at ebay, where a 1" OM H-type SU Carb is up for grabs, the question is again asked as to which needle is right for A7 set-up. Can anybody enlighten?


See:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=330192276946&ssPageName=STRK:MEBI:IT&ih=014

Take care !! This SU will not fit directly on to your A7 manifold without a purpose made adaptor!!
Regards John

I have a beautifully hand-made from solid alloy adaptor for this purpose. Has been sat in desk drawer for about 15 years, never fitted. Email Writdirect@aol.com if interested and I will try to provide a quick digital pic or two.

See thread - SU Carb? by Steve Martin, Jul 26 2006 - 6:09 PM. Fifteen replies to this thread including one from me.

Jeff.

What is the right needle for one Seven engine fitted with an SU isn't always quite right for another Seven engine but, as a start, M9 or BA should get you going.

Remember that it is only going to be the top part of the needle that has any effect as the engine won't produce sufficient 'suck' to lift the piston much higher. If the carb has a bronze piston, it won't have a spring. If an alloy piston, use a 'Blue' spring.

If you need an adaptor, they are easy to make but a pre-war OM should bolt straight onto a Ruby type manifold.

STEVE

SU needle I use a red spring and a eb needle on my 1inch su