1955 BSA B31 Plunger


First Registered 1st March 1955
New document V5c Historic Taxation class. (No road tax or MOT requirement)
Old buff logbook comes with motorcycle.

Frame No. BB31S-12796
Engine No. BB31- 4383

Motorcycle Reg is PAS 501
Mileage: 29700 (cannot be verified as correct)

The motorcycle frame and engine are unmatched in that the frame is original 1955, but fitted with a 1953 engine at some point in its life. Verification for this info is via BSA Owners Clubs librarian letter.

Restored to a good standard and to as original specification as possible. The frame is rear plunger suspension in black stove enamel with telescopic front forks. Starts easily, usually first or second kick, ticks over smoothly, rides and performs very well.
BSA created lovely riding positions in these vintage bikes, and this motorcycle has a large single well sprung saddle that makes it a very comfortable ride.

There will be a video attached to this once eBay review it. If you like to view a video then message me an email address.

Recent upgrades:
Brand new handbuilt AMAL Carburettor fitted (receipted). The wrong carb was fitted causing the motorcycle to not start easily and run very lumpy.
Complete new clutch, push rod and adjuster ball bearing as clutch was very heavy with little clearance.
Timing cover inner oil seals replaced.
Decompression mechanism refurbished.

Bike comes with original owners handbook, reproduced service sheet book, and various documents.

These old BSAs are very popular models and this is a very good investment.

Print & Share

Do you have unwanted jewellery or precious metals with value that could go towards a classic bike purchase? Visit Precious Metal Exchange to sell your unwanted jewellery or precious metals for cash.


  • Engine Size:350cc
  • Odometer:29700 miles
  • Registration:PAS501


Buy on Finance


If you are interested in this bike, please contact us on 07932 577377 (9am to 5pm Monday to Friday) or by email.

Viewings are welcome by appointment (Monday to Saturday) at our facilities in Gloucestershire.

Delivery available to anywhere in England and Wales for £120.

Sign up

Receive an email whenever we add new bikes to the website and see our new stock first:

See also: