BSA B40 350 Star

Goal was to strip down the front end and be left with both (A) and (B) as the front suspension removed from the assembly.

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Removal of the handlebars did not pose any issue (easiest part of the day).

The sheet metal (C) will not slide up over or down so essentially the suspension should be removed first.

I was looking to remove the Nut at (E) which would allow the top part of the steering yoke to be removed vertically up (allowing (C) to also slide up and over), but after speaking with Douglas Jones his suggestion made the most sense.

Per Doug’s suggestion I will take the nuts removed earlier from the tops of the tubes and use them to remove the suspension tubes. I will thread them back in down to the bottom and then back them out just 1 thread to keep maximum thread engagement. I can then use a piece of hardwood on top and pound them down (proper assembly support) to push them out of the taper wedge. This can be done for each and should help remove them from the assembly.

With the tubes out of the assembly the sheet metal (C) will slide down and leave (D) and (E) to be removed next.

The nut (E) is now rounded and already the wrench was slipping. (some corner metal was left in Scotland) Will likely need to have help from the neighbor to weld a large nut onto the top of the component (E) so that my impact wrench can be used to release and disassemble the stem.

The Ammeter was in spot (C) of the headlamp but it was no longer electrically connected in the circuit (prior issues). The wires were all on one of the terminals, so I deduce that it was already causing some issues prior to storage. The unit was also put in using some type of Scottish goop. I hit it with the heat gun to create soft goop and for sure it started to peel away, but then within a few minutes the ammeter fell apart… guess it was also made of more plastic than I realized. Will be adding one of those to the shopping list :o)

The unit had 4 slot screws and nuts where (A) is shown above equally spaced around the inner ring. Had to get my neighbor over so that we had 4 hands. Two trying to keep the screw head from spinning and two to get the swivel socket on the inner nut and turn it to ultimately snap the bolts. I think all of them broke, but replacing them with small stainless steel nuts and bolts will be the repair.

The front fender is removed and now just to remove the components before cleanup. those bolts might not survive the removal process, but are bound to be replaced in order to remove the 50+ years of rust and grime.

The state of the steering column lock nut above did make me aware that Willie had likely done some work to this area during his 10 years of riding fun.

If the odometer is correct and accurate then 25361 Scottish miles was put on this bike which is around 2500 per year. Not bad in the Scottish summers :o)

Off for a CVMG Breakfast in Chatham ride tomorrow, so likely trying to get the suspension removed and the rest of the steering column disassembled tomorrow afternoon. Mario told me to be ready to catch the 48 ball bearings and in the past they would put some magnets around on the floor to help catch the balls. Not too hard to replace but will see if I can get a cardboard box underneath when we start separating the steering column.

Not sure I thought I’d get this far today, but here we are. I started today with the foot pegs and pedals as a goal. The right one (gear lever) is still attached—mainly because the bolt/nut is now perfectly round. Definitely on the replacement list. I even wondered if it was reverse thread (still trying to find out), but whichever way I tried, it just sneered at me. I’ll get later to the fact that the gear lever is on the right and the brake pedal is on the left.. total opposite from all our other bikes… hmmmm. Not sure why this just due to the left side driving, but here we are.. discovery.

The brake-side foot peg and lever were a bit kinder. The foot peg nut turned out to be reverse thread (thank heavens for small mercies). The brake pedal, though, came with its own bag of tricks. One wee nut had a cotter pin that had rusted in place—took more finesse than a Glaswegian trying to eat soup with chopsticks. There is also the brake-light switch which is going to need some love and attention.. wonder if it was working in the end… at first glance I’d guess not.

Next came the sheet metal that holds the battery and assorted bits, which of course led me straight into battle with the shock absorbers. Those, in turn, demanded the fender come off, which politely insisted that the rear wheel had to come off first. This BSA clearly has a sense of humour—every step feels like being told, “Aye, you could do that… but not until ye’ve done three other jobs first.”

Looks like a bit of a bees nest in there.. but it and the brackets all came out ok.

The upper bolts for the shocks were tighter than a Scotsman’s grip on his last pound note. Just when I was about to admit defeat, my neighbour wandered by. With the two of us and a hammer (the ultimate Scottish torque wrench), the shock absorber finally waved the white flag.

After that, I removed the wiring harness and then the electrics inside the headlight—the 1960s version of a modern fuse box, except with fewer safety standards and a lot more character. Grips and electrical connectors came off the bars to allow everything to snake through the headlamp.

Now the bike is rather bare (phew), stripped back to a skeleton. Next job is the front wheel and forks—but that’s a story for another day, once I’ve had a strong cup of tea (or perhaps a dram, depending on how the bolts behave).

Lets’ start with the death shot image to the left

Ok… so the exhaust is removed. At first glance it appears to be a success — but not the kind of victory I had in mind. I was picturing a clean, one-piece removal, like pulling a sword from a stone. Instead, it was more like digging up an ancient fossil with a jackhammer.

Sure, the pipe was so rusted it wasn’t going to win any beauty contests, but technically it was doing its job. It did function as a “silencer,” though in that very British way: it didn’t silence much, it just made the noise sound slightly more polite.

Now, here’s the fun bit: the pipe is held on in two places (A) and (B). The whole system is actually two pieces joined with one pipe sliding into the silencer, clamped at (C). Easy enough in theory. Except the section in the yellow box passes through the kickstarter, the foot peg, and the gear shift. Once everything was loose, you’d think the pipe would just slide out with a cheerful “pop.” Nope. Instead, it was like trying to solve a mechanical Rubik’s cube designed by someone who hates you.

Removing the foot peg should have made it possible. But of course, the bolt and nut had other plans. The foot peg bend blocked a socket, and a spanner? Useless. Too close to the ground, bad angle, no leverage. The open end managed to get on one set of flats, but with enough pressure it started rounding the corners. Arrgghh. At that point I summoned the pneumatic impact — my Excalibur — but all it did was create rounder nuts, inside and out. Almost heroic, but not quite.

Enter the Sawz-All. When 50+ years of engineering stubbornness meets modern reciprocating fury, there’s really no contest. Let’s call it: Engineers 0 – Sawz-All 1.

Oh, and the kickstart? That had its own little trick — a wedge piece pulled into the lever to hold it against the shaft. Over time, the pin had collected more dents than a bumper car, and it fought me every inch of the way. It’s now on the shopping list.

Finally, the exhaust pipe — slip fit into the cylinder, held with a bracket. I had a quick sanity check call with Mario (every restorer needs a “Mario”), who confirmed the finned ring casting was just a heat relief and could be removed later. Good to know I wasn’t about to dismantle something sacred.

Next up: engine removal.

If the exhaust was this much fun, you can only imagine what’s coming next…

Not bad for $10 in scrap steel with some left over.

This is what it looks like so far. My neighbor did the welding and it’s tricky to do the tack welds and then how to keep everything square and aligned as you fill the welds (heat warping the steel). The part on the left we made so it fits together with a joint so that it can be removed. It’s only required if you tip the assembly down to work on either side of the motor.

I spoke to one of the CVMG guys (mechanic) and he said back in the day they just put them in a wooden box (remove sides likely) as an engine holder. Of course not so easy to find a wooden box anymore as that was likely when vegetables came in them :o)

Next steps are to get some black rattle can paint and put a few coats on it with maybe a coat or two of clear coat… then I will put in the plastic plugs for the ends that I got from amazon,

I still have to measure and drill the holes to mount the engine before I do the pretty work and before it starts rusting…..

I had already rebuilt the carburetor, but took it apart and after cleaning the needle seat I reassembled and no more tickler valve leak :o)