BSA A7 Engine rebuild advice
Discussion
I have a 2 owner 1957 A7 with 45,000m that I am overhauling, primarily due to worn bores.
Its never been apart before so it’s thankfully free from previous hammer and chisel type damage.
I have done some research but really would like some advice on who to trust for parts and what modifications/improvements to do whilst its apart. It was taken off the road 30 years ago so I presume the head will need adapting for modern fuel
Hoping to freshen it up back to standard 22bhp rather than hot rod the engine.
Its a cooking, iron head single carb job in remarkable original condition for a 65 year old machine.
Its never been apart before so it’s thankfully free from previous hammer and chisel type damage.
I have done some research but really would like some advice on who to trust for parts and what modifications/improvements to do whilst its apart. It was taken off the road 30 years ago so I presume the head will need adapting for modern fuel
Hoping to freshen it up back to standard 22bhp rather than hot rod the engine.
Its a cooking, iron head single carb job in remarkable original condition for a 65 year old machine.
SRM used to be the go-to people.
https://www.srmclassicbikes.com/about
They did a ball/roller conversion for the timing side main bearing.
Which is probably not needed for a cooking 500.
It's a good ideal to split the cases and clean out the sludge-trap in the crank IMHO.
From what I recall, the actual engine is likely to be the least of the problems
The main issues might include the joy of all the oil draining into the sump if you don't run it for a while and getting sense and reliability out of the magneto and dynamo/regulator.
Also recall chronic incurable clutch drag and quite awful brakes.
https://www.srmclassicbikes.com/about
They did a ball/roller conversion for the timing side main bearing.
Which is probably not needed for a cooking 500.
It's a good ideal to split the cases and clean out the sludge-trap in the crank IMHO.
From what I recall, the actual engine is likely to be the least of the problems
The main issues might include the joy of all the oil draining into the sump if you don't run it for a while and getting sense and reliability out of the magneto and dynamo/regulator.
Also recall chronic incurable clutch drag and quite awful brakes.
The head will be fine,just run it on vpower or similar.
clean out the sludge trap in the crank.
Being a relatively low power A7 it will be bullet proof.
Get the dynamo chain just right, too loose it rattles, too tight it whines.
where are you in the country ? My source of A10 Super Rocket parts is F&D motorcycles in Great Dunmow, Essex.
Nick is the man , really knows his stuff
If yoy have magneto or dynamo problems - Mr Salmon, Burnham-on-Crouch, 01621 784141
clean out the sludge trap in the crank.
Being a relatively low power A7 it will be bullet proof.
Get the dynamo chain just right, too loose it rattles, too tight it whines.
where are you in the country ? My source of A10 Super Rocket parts is F&D motorcycles in Great Dunmow, Essex.
Nick is the man , really knows his stuff
If yoy have magneto or dynamo problems - Mr Salmon, Burnham-on-Crouch, 01621 784141
Thanks for your recommendations DS
Interesting to hear that it will run on unleaded, I thought I might have to go to the expense of fitting valve seat inserts, something I can’t do myself.
My main concern is which pistons to use as originals are no longer available whilst some replacements are of dubious quality or so heavy that the crank would need rebalancing if chosen.
Interesting to hear that it will run on unleaded, I thought I might have to go to the expense of fitting valve seat inserts, something I can’t do myself.
My main concern is which pistons to use as originals are no longer available whilst some replacements are of dubious quality or so heavy that the crank would need rebalancing if chosen.
kev b said:
I have a 2 owner 1957 A7 with 45,000m that I am overhauling, primarily due to worn bores.
Its never been apart before so it’s thankfully free from previous hammer and chisel type damage.
I have done some research but really would like some advice on who to trust for parts and what modifications/improvements to do whilst its apart. It was taken off the road 30 years ago so I presume the head will need adapting for modern fuel
Hoping to freshen it up back to standard 22bhp rather than hot rod the engine.
Its a cooking, iron head single carb job in remarkable original condition for a 65 year old machine.
HI, i have been in the motorcycle cylinder business since the early 90s so know the boring, honeing and sizing of the bore. Its never been apart before so it’s thankfully free from previous hammer and chisel type damage.
I have done some research but really would like some advice on who to trust for parts and what modifications/improvements to do whilst its apart. It was taken off the road 30 years ago so I presume the head will need adapting for modern fuel
Hoping to freshen it up back to standard 22bhp rather than hot rod the engine.
Its a cooking, iron head single carb job in remarkable original condition for a 65 year old machine.
What i cannot offer advice on is suitable oversize pistons, i mainly deal with Japanese and European brands. The new remanufactured pistons offered are usually made in China. You would be best trying to find some NOS pistons of you can.
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