Yes it had to be bought, it weighs 15kg!my engine revs at 1200rpm when i am just going steady, its not too noisey at this speed and does not make the crockery rattle! the lister had a 200mm o/d fly wheel on it, the alternator shaft is 30mm ! i have had a new fly wheel cast twin groove z section, 260mm o/d and managed to get a 67mm pilot bore pulley machined out to 30mm inside o/d with a 8mm key way. This set up has given me a ratio of 3.8 /1 which even on tick over 550rpm gives an alternator spindle speed of 2134 revs, at 1200rpm it gives a alt speed of 4560 rpm, sounds good in theory, will report back when the fly wheel is deleverd . And i have managed to fabricate 2 sets of altenator brackets, one for the feeble 35amp 12 volt altertnator for the starter motor, (could not source a 24 volt starter motor )and of course one for big bertha, still struggling to work out the tensionong on bertha though, as i posted several months, the days of the sr4 plodding along not under load are over! she wont know whats hit her,