The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: fj12jagman on 17.10. 2010 23:35

Title: 1952 A10 Complete strip down and re-build
Post by: fj12jagman on 17.10. 2010 23:35
I am new to the forum and might not be very good at searching, please forgive me if these are obvious questions.A few years ago I bought what appeared to be a complete 1953 A10, certainly a rolling chassis. It came with a new wiring loom, tyres, carb, battery and the tank which was away being chromed. I later collected the tank, duly chromed but with a 1" dent just forward of the left chrome 'teardrop'.
I took a series of digital photos as I stripped the bike, right down to the colors of wires attached to various components. Thought I was really clever until my computer crashed. *eek*
I have completely stripped the engine. Whilst I have experience of doing this on my first car (1965 Morris Minor neraly 30 years ago) I do not have the engineering training some forum members obviously have. I have an extensive collection of spanners/sockets etc but no calibrated measuring kit, dial gauges/micrometers etc and wouldn't know how to use them anyway. I do have the original service sheets and full parts list.
I intend to get the crank checked and re-ground if necessary. I am grateful to the forum for advice about the radius and getting it nitride treated. *smile*
How do I check if the bronze bushes in both cases are worn out? ????
I will be checking the bores, or get someone else to do it.
Is there any general advice about re-building the engine or can anyone point me to where I can find the info?
Title: Re: 1952 A10 Complete strip down and re-build
Post by: BSA_54A10 on 18.10. 2010 00:51
Some measuring instruments would be a good idea but not essential.
Every thing that needs to be measured can be done with a set of feeler gauges.
And yes you can check the bore with feelers, it is just a tedious job.
As for bushes, it is a case of feel.
Shafts should rotate freely but there should be no perceptible play, up down, left right.
If you can wobble it about then it is replace time.
These motors were made to be rebuilt on the kitchen table when the "missus" was out shopping.
We have a bad habit of over engineering things, just because we can and forget that when A10's were new, most mechanics did not own 1/2 of the complicated measuring gear that we have sitting in out workshops, tension wrenches were things that they learned about in college and may have actually touched once.

OTOH with the aid of modern tools & equipment we can make the bikes run much better and more reliably than they did when new. Talk to some old timers, blokes who owned them from new & rode them on a daily basis. In 1950 ( & 60's) no one noticed ( or cared ) about the puddle of oil under the bike unless it dripped onto our new Roul Mertons ( hard to get oil out of suede ) and as for smoke from the exhaust, it was more a case of pick the clean one.
I have a 1974 Rolls Royce which still did not have an oil seal on the crank so if you park it on an angle the contents of the sump ends up on the ground and they were considered the epitomie of motoring at the time.
Title: Re: 1952 A10 Complete strip down and re-build
Post by: bsa-bill on 18.10. 2010 09:38
got it on one there Trev
In the sixties sockets were for the professional, rest of used box spanners with a hole in it and a big screwdriver, hammer, the spanners that came with the bike and an adjustable
Title: Re: 1952 A10 Complete strip down and re-build
Post by: Goldy on 18.10. 2010 11:44
Welcome fj12jagman. You will find in other parts of this forum lists of books and literature that are available. The book by Roy Bacon - BSA Twin restoration is usefull. The first decision is knowing what to replace ( you mention the main shaft bush ) well I would replace them anyway. Bearings, bushes and oil seals are not usually worth keeping anyway. You will find members of this forum have a real knowledge of these machines so just keep posting your questions. All the best.
Title: Re: 1952 A10 Complete strip down and re-build
Post by: dpaddock on 18.10. 2010 13:39
Look at BSA Service Sheet No. 207 for crank regrind info. IMO, nitriding is not warranted.

Title: Re: 1952 A10 Complete strip down and re-build
Post by: fj12jagman on 19.10. 2010 00:02
Thanks to all.  *smile*