If you just have a weber carb on an A15 then you could get away with a 2 inch system but if you plan to fit a big cam and some sidedraughts you would want either a 2 1/4 system or even a 2 1/2 inch system since the A series engines love to breathe well, extractors are a good upgrade you could find a second hand set on ebay easily or buy a set from jeff taylor or ferrol errol at datrats

hi all, Just interested as what exhaust set ups others have in their 1200. I currently have a A15 and no real mods besides a weber carby. My problem is every exhaust shop i go to tell me different things, some say i nedd a 2 inch others 2 and a half (which im pretty sure is a bit big). I was wanting to also get extractors to complete the system. There have also been huge price variations anywhere for 400 for the lot through top over 1000. What would others reccomend and how much do you think is a fair price to pay, any help would really be appreciated.

Cheers
andrew