hi there just bought an m20 in a number of boxes but cannot place the engine numbers.the story was it came from pakistan many years ago and has been in a shed in pieces ever since.the engine and frame number are the same and do not seem to have been altered they are a50 ra . 14714 which to me are an a65/a50 frame number.it is a plunger and seems to have been maroon in colour the rear hub is qd but there is no number plate or id plate as rear guard is missing any ideas or help would be appreciated

email (option): jeffwinton@aol.com

Hi Jeff

The numbers don't look at all like an M20. I guess the parts don't look like an A50 though?! According to http://www.sunnymeadcycles.com/files/BSA_ID.pdf that would be a 1967 Royal Star, but the number itself is high. Post some photos and I'm sure someone will have more idea.

Richard

email (option): Dickie.bobbie@hotmail.co.uk

Hi Jeff,the engine number is located on the drive side just behind the breather
below the cylinder base.The frame should be a rigid or plunger,the A65 was
always a swing arm frame.The number should be on the left side of the headstock
as you are sat on the bike.
Good luck amd welcome to the forum
cheers Rick

email (option): richardholt@rocketmail.com

Hi Jeff...The splined 'crinkle' QD rear hub would be standard fitment for plunger models..

Regarding numbers I have seen bikes from the middle and far east that have been numbered by/for Government bodies to match the numbering system of that body.. These numbers appear to be completely original and not 'messed with' but don't comply to normal BSA numbering sequences..
BSA supplied plunger models to numerous countries both for government and civilian use...
Civilan models always comply to normal BSA practice...

The other obvious possibility is that the bike has been renumbered to match a log book or some other paperwork requirement..It may even have been used in a registration number transfer...

Usually in these cases the alteration can be spotted, either because the size or font style of the stamps used was incorrect, there are signs of the old number being removed (file marks, a flat spot on the tube) or the number is in the wrong location for the model...Ian

email (option): ian@wright52.plus.com

thaks for reply bit puzzled engine number is on drive side case but there is no breather. breather is in timing side case. no obvious signs of being renumbered either engine or frame it is a plunger but given that it is in cardboard boxes anything is possible.not worried if its a bitsa will rebuild and see what turns out regards jeff

thaks for reply bit puzzled engine number is on drive side case but there is no breather. breather is in timing side case. no obvious signs of being renumbered either engine or frame it is a plunger but given that it is in cardboard boxes anything is possible.not worried if its a bitsa will rebuild and see what turns out regards jeff

Hi Jeff..The breather on the drive side crankcase below the barrel (and next to the engine number) was discontinued from August 1947 onwards..
Later models such as yours had the breather relocated to the timing cover....Ian

email (option): ian@wright52.plus.com

Hi Jeff,have you any photos?Im curious now what you have got
cheers Rick

email (option): richardholt@rocketmail.com

hi there the plot thickens just stripped frame back to cut off the aftermarket add ons and the origional paint is blue the engine cases have a grey colour which takes some getting off dont thinks the maroon is origional as its metallic will send you some pics when daughter shows me how to isnt old age fun regards jeff

email (option): jeffwinton@aol.com