between about 35 and 100.. depends if you want a light weight one, which will make it rev easier... if not, i bought http://cgi.ebay.co.uk/ws/eBayISAPI.dll?V...TQ:GB:1123 which is fine...
http://www.ebay.co.uk/sch/i.html?_from=R...aft+Pulley
http://www.ebay.co.uk/sch/i.html?_from=R...aft+Pulley