Evening All
Can you please advise the valve clearances for a 1949 B31.
Thank you
BUNNERS
Google search returns this
For a 1949 BSA B31, the valve clearance should be set to 0.003 inches (0.076 mm) for both the inlet and exhaust valves. This is also referred to as .003".
Important Considerations:
Engine at TDC:
Valve clearances are typically adjusted with the engine at top dead center (TDC) on the compression stroke.
Tappet Foot Position:
Ensure the tappet foot is resting on the base circle of the cam lobe when adjusting.
Proper Technique:
Use a feeler gauge to measure the clearance and adjust the tappet until the correct clearance is achieved.
As Mark says, .003" inlet and exhaust but the inlet clearance should be set when the exhaust is on the point of opening and the exhaust clearance set when the inlet has just closed. Pic from the manual below.
Quote from: BUNNERS on 13 Apr, 2025, 16:17 Evening All
Can you please advise the valve clearances for a 1949 B31.
Thank you
BUNNERS
A set of relevant Service Sheets may be a good idea?
Quote from: V500 on 14 Apr, 2025, 18:35 Quote from: BUNNERS on 13 Apr, 2025, 16:17 Evening All
Can you please advise the valve clearances for a 1949 B31.
Thank you
BUNNERS
A set of relevant Service Sheets may be a good idea?
All the service sheets are available from this website in New Zealand! https://bsa-info.nz/service-sheets/ (https://bsa-info.nz/service-sheets/)
Service sheet 604 "B & M group Engine adjustments" is the most relevant.