928 Concentric Carb

Information relating to the Matchless G12 or AJS Model 31 650cc twin
Locked
tracyawuk
Member
Posts: 15
Joined: Sat Apr 24, 2021 12:25 pm
Location: Devon UK

928 Concentric Carb

Post by tracyawuk »

Hi I've got a 1960 C31 CSR that sometime in its life has had a 928 concentric carb fitted. Just took it apart to clean service it and found it has a 360 main jet fitted. The pilot and needle are the sane as listed for the mono bloc but the main is different. 360 as against 450. Just wondered why that would be? Do the concentrics s flow differently? Bike seemed to run ok just cleaning the carbs as the bike had just stopped ticking over. Any thoughts?
User avatar
dave16mct
Member
Posts: 3234
Joined: Mon Jan 01, 1990 12:00 am
Location: LANCASHIRE UK

Re: 928 Concentric Carb

Post by dave16mct »

Concentrics use a main jet 20% less than a monobloc, so it sounds about right.
Dave
tracyawuk
Member
Posts: 15
Joined: Sat Apr 24, 2021 12:25 pm
Location: Devon UK

Re: 928 Concentric Carb

Post by tracyawuk »

Many thanks Dave
Locked