Restoration of my Motorcycle





Stop sound if you wish.

My BSA project
1951 BSA B31 350 cc single.








I used to ride a motorcycle many years ago, when I was transferred to Jamestown, in country South Australia. It was in the early 1970s.

It was a 1951 model BSA B31 with a rigid frame, and a 350cc cast iron engine. I bought it second-hand, after seeing an advertisement in the newspaper. I paid $80 for it, and it was one of the best buys I ever made. It would go all day without any problems, and it was quite easy to start and was always dependable. Although it had some piston slap and made a bit of noise, and used to burn a bit of oil if I let it stand around for a week or two without being used, it never let me down while riding to work five days a week, and at weekends while I was riding around those country roads near Jamestown. After I transferred back to the Adelaide metropolitan area, it continued to be a reliable commuter bike for several more years.



I sold it some years later for $100, which to my mind then was cheap motoring for five or six years. I have regretted selling it ever since - I should have kept it in a shed. Hell, I could have ridden it a few times every year, and had a good time instead of just reminiscing about how much fun it was.

Bugger all this reading and writing - just show me the pictures


FEB 2002:
I took early retirement from my job at the age of 55, and I thought that I would restore an old British motorcycle, and ride it in rallies such as the Bay-to-Birdwood rally. I thought that a BSA Bantam would be a good choice, since they were so popular and so many were made. I didn't think that I would ever get hold of an old B31 like I had before.

JULY 2002:
Still no luck. I have been looking for a BSA Bantam or C11 for several months, but nothing suitable has been advertised in any newspapers or magazines.

A friend of mine, Geoff, who has shared the same interest in old British motorcycles talked me into going to a meeting of the The BSA Owners' Club of SA. His son actually found an old motorcycle for him to restore, a BSA A7 twin just like he used to ride years ago, and bought it for him. The three of us joined the club later that night, after attending the meeting and talking to some of the members.

AUG 2002:
I have been looking around for a couple of months, but I couldn't find a suitable bike - until now. I heard that Stanley, another member of the BSA Owners' Club, has a B31 for sale - almost exactly the same bike as the one I owned thirty years ago. Mine was a 1951 rigid-framed model, but this is the plunger-framed model from the same year.

It is in pieces, but Stanley says that it is all there, and the motor and wheels have already been reconditioned. I will have the frame and major pieces powder coated, and paint the tin-ware myself. I'll get the nuts and bolts and fittings zinc plated, and then begin to assemble it.

Stanley has restored several motorcycles and knows what to do - with his help, and also Terry and Rob and Greg, I should be able to do a lot of the work myself. Otherwise it might take me a long time, and cost a considerable amount of money. I have plenty of time since my retirement, but not a lot of money.

The BSA Owners' Club is a group of like-minded people who have an interest in old motorcycles, and help each other restore them, and go on motorcycle rallies, and I have found a number of people who are willing to help me restore my bike. Many of the members of the BSAOC are older than I am, with a few younger members included. There are more than 150 financial members from all over South Australia and interstate.

OCT 2002:
I have had to replace the piston, and have the cylinder bored out. The valves, seats and guides had been reconditioned, but not the rest of the engine, apparently.

Anyhow, I got a couple of friends to do the work, but it cost more than it should have - don't believe anybody who tells you "it's all been done ... it's all there". I have learned a valuable lesson - if you can't see the bike in running order, be very wary!

NOV 2002:
Now that I have retired, I can indulge myself a bit and do whatever I want whenever I need to, unlike the wage slaves at work, just thinking about it and wishing they had the time.

I would have liked to do this years ago, but could never find the time with work and family commitments.

FEB 2003:
I have got the bike home now, but unfortunately some of the missing bits are the speedo, voltage regulator, tail light, exhaust pipe and muffler ... and the arm which activates the valve lifter - I will have to find them and get them. Of course, they are the hardest-to-find parts ... that's why they are missing. More unexpected hassles.

I have managed to do some of the finishing touches required - like adapting the original headlight shell to take a modern sealed beam unit, and fitting all of the cables and the toolbox. Not only will I have to get a muffler and exhaust pipe, but I will have to replace the front and rear tyres, which are buggered. Just a matter of saving all my loose change until I can afford it!

I have ordered a new exhaust pipe and silencer. When that is ready I should be able to start the engine, and tune it. A retired friend, Terry, has offered to help me to do this as soon as the exhaust and silencer are fitted.

28th FEB 2003:
Today I got a call from Terry Merritt, of Redline Exhausts at Melrose Park. The new exhaust and muffler I ordered was ready, so I rushed down to pick it up. When I got it back home, I fitted it straight away.

It looks perfect - Terry has done an excellent job. I can't wait now to start the engine and then get it running.

11th APRIL 2003:
I pulled off my rear wheel and took it down to the Marion Trade Centre today - to HANBY'S MOTORCYCLE TYRE SERVICE.

Russell Hanby was really friendly and helpful - and he actually had a choice of three types of the old classic 3.25 x 19 tyres in stock. I have been pleasantly surprised by the service and assistance I have received from people like Russell Hanby and Terry Merrett (of Redline Exhausts), who own their business and work there as well.

In many places I have been to for old motorcycle spares or parts, the bloke behind the counter has just laughed at my request with some sort of philosophical quip like "Jeez, mate - you'd be lucky to find one of them in Adelaide." No offer to help, no suggestions or recommendations, etc.

But Russell and Terry have been great. I thoroughly recommend them to anyone living south of town (or elsewhere in Adelaide) who is in the frustrating process of restoring an old motorcycle.

12th APRIL 2003:
I pulled off my front wheel and took it back down to Russell Hanby. He fitted and balanced the tyre and tube and I was back home in under an hour. It didn't take long to replace the wheel. Now the bike is starting to look better!

27th APRIL 2003:
Today I started the engine for the first time. It has probably not been started for ten or fifteen years, but Terry assured me that everything was now done and it should start relatively easily.

Want to listen to it?

It took quite a bit of effort to kickstart it the first time, but I remembered all the tricks I used to use in the 1970s - not bad for an old bloke, eh? I had to kick it over more than twenty or thirty times on that first occasion, but it eventually ran (even though I couldn't for a couple of days).

MAY 2003:
I have run the engine several times now. Each time it only takes about two or three kicks to start it, and it seems to run quite well, although it doesn't want to idle without a few twists on the throttle, in spite of me adjusting the cable. Perhaps the carburetter needs work.

It leaks petrol a bit, but I am hoping that if I gradually tighten all the carburettor fittings, etc, the fibre washers will take that up. I lost a little bit of oil from the breather at the bottom of the timing cover, but I suspect that was oil which had settled there over the last couple of months. Maybe the ball valve down there needs a little attention to seal it properly. I will get an expert to have a look at the bike and let me know what else has to be done. It shouldn't take long then ...

AUGUST 2003:
At the annual general meeting of the BSA Owners' Club I was elected Librarian, and I am now responsibe for the club's extensive collection of manuals, service sheets, books, videos, etc.

I have always been interested in old books and magazines, and have reproduced several old manuals, which are no longer commercially available, by scanning and editing them and printing them on my laser printer, and binding them and trimming them to size. The finished product is pretty good, if I do say so myself.

10th JANUARY 2004:
I have done quite a bit of work on the bike recently - nothing major, but lots of small jobs, like replacing clutch springs, adjusting cables, etc.

When the 1951 models were released, the petrol tanks were painted green with gold highlights, rather than chrome plated, because of the world-wide nickel and chrome shortage after the war. So I painted my petrol tank green, for this reason. I have not yet finished the tank, but I am pleased that it has gone so well after the first few coats.

What I need now is a mechanic familiar with old bikes. There are members of the BSA Owners' Club who have done some work for both Geoff and his son, but they are unable to do the work on my bike for quite a while - they are snowed under with work, apparently. I also need a motorcycle mechanic closer to where I live, to let me know what still needs doing to my bike, and to fix it up.

FEBRUARY 2005:
I tried to adjust the clutch, but couldn't seem to get anywhere. I followed the instructions in the manual, but there seems to be some problem preventing me from getting the clutch to fully release and engage. It is as though the control rod is too short, or something else is wrong. I have had trouble finding a motorcycle mechanic who is confident or willing to work on a 1950's BSA - at least in my local area. There are some in the northern suburbs of Adelaide, but getting the bike to them is a bit of a problem for me. I will continue to check out the local club members and other motorcycle clubs ...

6th JULY 2005:
Stanley brought two friends to my place today, Paul and Mel. Mel knew a fair bit about B31s, and it was easy for him to diagnose the problem with the clutch - the clutch hub is from a different bike, a B33, and it is different to the B31 hub to allow for extra clutch plates for heavy duty use with a sidecar. Stanley had another clutch hub (the right one this time) in a bucket of parts he had brought along. He and Mel fitted it, and reassembled the bike. We adjusted the chains, and filled the oil tank and put in some petrol, and kicked the thing into life. It only took two or three kicks to start it ... not bad after sitting neglected for many months covered with sheets in a corner of the shed. The engine runs well, except for a little popping and spitting - it is as though air is leaking into the cylinder past the carburetter slide, or perhaps the mixture is wrong. But the engine runs well, and the bike is rideable.

We rode it around the street in front of the house, and changed gears up and down. It works fine now, although to be safe I will recondition the clutch plates, which look a little worn. I might also get new chains while I am at it, to avoid any problem further down the track (?). Many thanks for the help, Stanley and Mel.

AUGUST 2005:
I have ridden the bike for short distances up and down my local street several times now, and each time the bike starts after one or two kicks, and it seems to run better every time. (Or am I imagining it?) It does pop and spit a little, and doesn't want to idle without a few little twists of the throttle. I might get the carby looked at ...

6th SEPTEMBER 2005:
I took the carburetter off the bike, and asked Ian, a member of the BSA Owners' Club, to recondition it for me, because when I rode it around the street, the engine popped and spat a few times. Ian rang me the next day - the wrong carburetter! Mine was from a BSA model M21 - much too big for the 350cc engine of the B31. He happened to have a replacement carby of the correct type, which has been reconditioned and fitted with an air filter. I agreed to buy it. Stanley has found a Smith's Chronometric speedo for me ... not the 80 mph speedo which the bike would have had fitted originally, but a 120 mph model. Wow! An increase in top speed of some 50% - now I will be able to really wind the old bike up.

Maybe I can have the bike ready for registration before Christmas 2005.

15th NOVEMBER 2005:
The "new" carburetter that I bought from Ian of the BSAOC has proved to be a bit of a problem. The mounting flange was not straight, and the mounting holes were not right. Stanley had to take it back to Ian, who re-ground the flange and bored out the holes so that it could be mounted on the bike. I had foolishly imagined when I bought this carby that everything would be perfect, but of course in the real world ....

22nd NOVEMBER 2005:
The carburetter slide does not slide smoothly within the carburetter body, and sticks in the open position when the throttle is fully opened. Again, I thought that this shouldn't have happened to a carby which was supposed to be fully reconditioned and as good as new. Rather than take it back to Ian, who lives about an hour away from me on the other side of Adelaide, I lightly sanded inside the top of the carburetter body, where some slight marks were evident, with a very fine emery paper until the slide seemed to close smoothly after fully opening the throttle. It seems OK now, and hopefully will work perfectly when re-installed on the bike. But these problems shouldn't have happened.

29th NOVEMBER 2005:
Bugger! The speedo deal has fallen through ... now Stanley and I are back to hunting around for a suitable one. They are not exactly common. I could get a replica magnetic speedo for about $275, but I would prefer to get a genuine Smith's chronometric speedo, even if I have to pay a little more.

15th DECEMBER 2005:
Today I bought a speedo from Andy, who is a BSA club member. Stanley found out that he had a reconditioned Smith's speedo for sale, and put me onto him. I needed it badly to finish the restoration of my motor cycle. It is a Smith's Chronometric speedo which has had the mechanism fully restored. It has been reset to zero, and is a real work of art. It was reasonably expensive, but they are hard to get and this one is really good. I have been looking for a long time now, and this is the first one I have found that wasn't junk, and didn't need lots done to it. And let's face it, the blokes who know all about these old instruments (and can restore them) are getting older and harder to find. Andy was really good - he came to my house with it and has offered to find a suitable cable to go with it. Thanks, Andy!

When I get the bike completely finished I will have to have it inspected, and the frame number and engine number verified. The engine number is easy to read (ZB31 18262, definitely a 1951 engine) but the frame number is a little bit harder to make out - (I think it is ZB31S 13249, making it a 1951 spring frame). One of the BSA Owners' Club registrars can check the bike over, and then give me a "historical registration" certificate so that I can register the bike and hit the road (?).

JANUARY to AUGUST 2006:
I have had a number of family problems and have not been able to do much about finishing the bike ... with a death in the family and some legal problems over the estate and probating the will it has been a rough time. Hopefully all that is over now, and we can get on with our lives.

29th AUGUST 2006:
Today John Simpson from the BSA Ownwers' Club came to inspect the bike. He is one of the club's Historical Registrars, and he issued a certificate which certified the bike to be in original condition with no significant modifications to the original equipment issued in 1951. I was then able to go to the Motor Registration Division with that certificate and a form showing other details and register the bike as a Historic Vehicle.

In South Australia that means that I pay three month's registration and register the bike for a full year. I can use the bike for up to 90 days over the next twelve months, but I must maintain a log book showing dates and places travelled.

SEPTEMBER 2006:
My wife and I went on a three week holiday to New Zealand. It was a wonderful holiday break. I couldn't get the bike back home before I left, so I made an arrangement with Stanley to look after it until I got back, and he would ride it to my house when I returned home. Stanley and the bike waited patiently for me to return home from New Zealand.

6th OCTOBER 2006:
Today Stanley rode the bike to my house, and I was pleased to hear that it went "beautifully" over the twenty odd miles he travelled.

It was quite a hot day, and there was a reasonable amount of traffic, apparently, but the engine didn't miss a beat, and Stanley sailed up the Main South Road past O'Halloran Hill effortlessly on his way from Thebarton to Woodcroft. He said that the steering was firm and the suspension worked "better than my A7".

Thank you Stanley. And thank you to all the other people who helped me - including Terry, Rob, Mel, Andy and John. I couldn't have done it without you.

Now, with only 19 miles on the speedo, I need to run it in and polish my old rusty skills before I can take the bike on some club runs. Unfortunately it is too late to ride it in the club rally this year.

At last ...


A quick pictorial history ...












Back to Home Page