SU NEEDLES

There is quite a debate about which is the best needle to use in a standard 1¼ in. SU carb. since, obviously, Burlin’s can’t give a definitive answer as Austin Sevens didn’t have SUs as standard equipment! The common wisdom says “A number 1 needle for road use and a number 6 for racing” but Ian Mason-Smith has found a way of selecting exactly which one you can use or, alternatively, if you have a couple of old ones lying around in a drawer, you can compare them side by side. Firstly, go on-line and type http://www.burlen.co.uk into the address bar across the top of the page (not the Google search bar slightly below). This will call up the Burlen’s web site. Click on “Click here to visit the SU website”. Then click on “Links” in the blue section at the top (shown) and on the next page, scroll down to click on “SU Needle Selection Helpers: - Chart to compare up to five needles”. You can then enter the number of any needles (up to 5) and their rich/weak characteristics are shown on a graph versus revs. Ian tried needles No. 6 and No. 1 with his current (850cc mini) EB and GY and AN that he had in stock . As can been seen in the original display, the GY and AN are virtually identical and the No. 6 gives a steady increase up the whole range. Many thanks to Ian for sourcing this article—Ed