B34-2 Rebuild

[Goldnrust]

Thank you for the heads up on the left hand thread, that is indeed news to me, so has saved me from certain head scratching in the garage.

I can report that I re-measured the wear on the small end, my previous measurements were over estimates I think. I've got a standard size from the Motorcycling magazine article of 0.6250-0.6255", and now I've remeasured I've come out at 0.626" sideways and 0.630" vertically. So 0.005" of vertical wear, less than the 0.009" I'd previously mis-measured.

I've carefully reamed the hole out on 0.630" all round, which suits the 0.629" (16mm) pin I'm using. I've only used fixed reamers before, and was using a cheap adjustable one this time, which I cannot recommend... but still the job is done. There's no vertical play any more, so thats great. There is a touch of 'rock' to the pin left, but it's a million miles better than it was.

I was able to ream the piston to match. It's possibly not quite as tight a fit on the pin as I might like, but there's no play and I'm sure it will be fine. Clearly this is a 'get me going' approach, and will likely be revisited in future.

While thinking of piston type issues, I re-inspected the bore and it was better than I remembered. A quick light DIY-hone to break the glaze and it's plenty useable.

I also received a new set of rings in the post. I couldn't find a spec for the ring gap for my bike, but did find specs for the C10 of 0.010". The C10 uses the same bore diameter and piston so that seemed as good a guess as any!

In a previous post I was wondering what the difference between the Hepolite 7150 and 7151 pistons was... the set of rings I have here for a 7150 have a 0.120" thickness oil scraper and my 7151 piston has a 0.160" oil scraper, so that might be the difference! I could hunt for a correct 7151 +60 oil scraper or, more probably given that no oil scraper was fitted originally, I shall just omit it for now and keep an eye on the amount of smoke.

In other news my new centre stand arrived in the post too, it's a 29-4883 which I believe is c11. I need to grind a bit of the casting away to allow it to fully fold up, but once that it done it's going to work nicely.

I've got a few more bits and bobs to sort on the engine side of things before it can start going back together, most importantly being that I need to machine a new cam bearing/bush as the inner one on my exhaust cam is spinning in the case. So I'm crossing my fingers someone buys my Daimler soon which will release the funds I need for a lathe!

One question, while I think of it, about the crank case breathing. I can see the crank case breathes through a passageway in the crank, which allows oil vapour to exit on to the drive sprocket and in turn lubricate the primary chain. From things I've read theres suggestion of a secondary breathing hole, possibly though the stud near the main bearing that holds the primary chain case? The stud on my bike here is solid, rather than hollow, have I misunderstood?

[Steve.S]

All sounds good to me.
I purchased some flanged oilite cam bushes from Brammer, Buck & Hickman. Part no. 213A7698. However, they have an OD of 3/4", so will need reducing to 11/16". Maybe you could try refitting yours with Loctite 648, but I would assemble the cam and timing cover while the loctite is hardening.
Well done solving the mystery of the 7150 and 7151 pistons.
BTW, while I remember, there should be a felt oil seal fitted into the deep recess of the crankcase hole for the crank shaft (if you see what I mean).
I think the stud you are referring to is the Primary Chain Oiler Stud, Part no. 29-584. This will have a hole drilled in it, to about half way, with a hole drilled at  a right angle to allow oil to drop onto the primary chain. You can see what it looks like in the Parts Book. Maybe a previous owner had fitted a normal stud to stop oil from leaking out and oiled the primary chain before each run. Blocking the breather off will, of course, increase crankcase pressure.

[Goldnrust]

Well, doesn't time fly! I've not had much chance to update, but progress has been made with my B2 rebuild.

I left off talking about the engine, which is now 90% done. Shortly after the last post I was able to purchase a lathe and learn the basics of using and and set about making some of the parts I needed.

Starting with the cases, I drilled out the broken remains of the lug for the primary chain oiler stud, turned up an aluminium plug and welded it in from behind. It could be a little prettier, but it was one of my first jobs on the lathe and will do the job perfectly well.

I also found that one of the threads for the studs for the barrel had been damaged, An oversize bolt jammed in there along with some liquid metal. Lovely stuff.... So I drilled that all out and made a custom stud that was larger on the case side but standard size to fit in the barrel.

I also fitted a new drive side bearing and made a new felt washer.

[Goldnrust]

The last job on the cases was to make a new cam bushing up. After some careful measuring (thank you new micrometer set!) I decided that the case looks like it was close to standard size and that someone had fitted the 'wrong' cam bushing, which was about 0.010" too small OD.

It took a couple of attempts but I was able to turn up a bushing that I was happy with and then pressed it into the case.

Crank next. I drove the worn thrust washers off, flipped them over to give me a fresh surface and ground a new chamfer on to that side. A make do and mend solution, but one I think will work just fine.

Measuring the big end I found ~0.001" wear on the con rod, the crank pin came up standard size and the rollers themselves were 0.002" undersize. I purchased new rollers and wit the unit assembled it feels perfectly acceptable to me. The crank was the easiest one to reassemble I've done! It still took some patient hours of truing but it responded predictably and I was able to get it to within 0.0015" of true, which was good enough for me!

With that the bottom end could go together, and I could think about getting the piston and barrel on. I made some bronze gudgeon pin cushions to suit my 16mm piston pin. They are a little deeper than the originals to make up for the fact that the 16mm pin is 0.030" narrower than the standard pin.

That all went together smoothly with the new ring to the piston gapped to 0.010", I couldn't find a ring gap spec for the B2, but that was a spec for a C10 and seeing as it's the same piston, that seemed a good place to start.

I cut a new head gasket from a sheet of copper. The head gasket I removed (some sort of composite gasket?) was 1.5mm thick, so that's what I went for with the copper. In hindsight I wonder If I should have gone thinner for a mild compression bump... Easy enough to swap out, if I want, at a later date.

[Goldnrust]

The head was the last major job for the engine. Thankfully the valve seats and the valves themselves looked pretty good, but the guides were quite worn. I turned up some new valve guides, and pressed them into the head.

The valve springs felt very soft to me, and I noticed that someone had put shims under the intake valve spring seat to try and increase the pressure! Lots of searching online with part numbers and I was able to score some NOS Terrys springs for a sidevalve B1, which have the same part number as the outer springs for the OHV B2. They certainly were an improvement over the springs that came o the bike. I re-used the old inner springs for now.

The rockers were thankfully in quite good condition. I stripped it all down, and removed some old carbonated up grease from the lubrication points, and was pleased to find no wear I the shatters or rockers themselves. The tip of the rocker, where it rides to the valve did have a little recent worn into it, but that was smoothed off in 5 mins with a diamond file.

And with that the engine is back together!

[Goldnrust]

Wow. It's been a long time since I updated this. Progress has been made!

With and engine and gearbox on their way to being functional, the frame was next on my list. As I noted in the first post, the lines of the bike all looked a little of when I got it. Not unusual or surprising for a bike of it's age. As I was stripping the bike down it became quite obvious that the rear portion of the frame was not sitting right. The engine and gearbox are offset from the centreline of the bike, which doesn't help when visualising it, but even so the dropouts are clearly twisted to the right.

Helpfully, in this case, the rear chain stays and seat stays are all separate pieces that bolt on to the front half of the frame. This made getting things straight a much simpler job. With a laser level, lots of measuring and patience I slowly tweaked each piece till I was happy the rear wheel sat nice and straight and square to the centre line of the frame.

As mentioned earlier in this thread, I'd picked up a cast C10 stand to replace my original 30's fabricated one that had defintiyl seen batter days. With a little massaging from the angle grinder, it fits nicely and now the bike will stand up straight and I can have confidence the stand will be strong.

With that sorted out, the next obvious piece of the puzzle was the forks. They had felt 'ok' when I got the bike, and look to be straight. Once apart a few issues showed up though. Firstly, the holes in both the girders and steering head for the lower links were worn oval and allowing some movement. Not an easy thing to photograph, but they were 0.020-0.030" wider than they were tall.

So I drilled the holes out and made a set off bronze bushes up on the lathe, and pressed them in. It's now a good fit, possibly a touch on the tight side as there's a little drag turning the links, but I'm sure with a few miles that will loosen up and better that way than to start with slop already in the joint that will only get worse.

The second issue with the forks was that the spring was broken. I hadn't noticed at first, but the top couple of coils had fractured off from the rest. By wrapping the two halves of the spring together the previous owner had been able to keep it riding, but I'd rather a more elegant solution.

Finding a replacement spring has proved tricky. Being a lightweight bike, it's smaller than many of the other springs out there. Whilst I could modify the upper mount for a different spring, the lower mount is a spiral cast into the girder forks on to which the spring threads. So I need a spring on the same size, and also that its wound I the same direction. I did find a promising looking spring but it was wound the opposite way to mine so wouldn't have threaded on to the forks.

After some weeks of pondering it, I decided to clean up the broken end of the spring then make a new top mount, that properly fits the trimmed up wider end of the spring and also accounts for the loss of spring length so the forks sit at the right height.

[Goldnrust]

But that's getting ahead of ourselves, before I started assembling bits the wheels had to be dealt with. Originally the bike would have had 19" WM1 rims front and rear on 19x3" tyres. The bike came to me with what I believe is the standard rear rim but the front rim was a WM2 front rim. Front rim wider than rear is likely to make for some interesting handling, so I knew I wanted to change one of the rims.

The rear rim turned out to be pretty rusty and also most of the appropriate style tyres suggest that you should have a wm2 rim for a 3" width, so the decision was made to go to wm2 rims from and rear.

Now hubs/brakes was the next piece of the puzzle. The rear hub seemed fine, a strip and regrease and all was ok. The brake seemed to be working fine, the drum surface wasn't amazing a bit rust pitted in places but it was passable. The rear sprocket though would need replacing, the teeth were heavily worn.... and it doesn't appear to be a part that's reproduced. Ah the joys of ancient vehicles!

Once again my little lathe saved me. I bought a modern reproduction sprocket from (...you guessed it) a C10 that happened to be the right tooth count for the right pitch chain, and used the lathe cut the teeth off as a ring. I then turned my original sprocket down till it was a nice fit inside the new ring of teeth and, once I'd added a nice big chamfer for weld penetration, clamped both parts to a nice big bit of steel box section and welded the two together.

One unobtainable sprocket problem solved. Excellent.

Now the front hub. This was not such good news. The braking surface looked bad, and once I'd started cleaning it up, it only looked worse. I did manage to mount it on my lathe, but it was really pushing the little lathe beyond it's limits and it soon became clear that if I turned it till the rust pits were gone then the hub would be perilously thin. It was looking like a job for a professional fix to get something safe enough I'd trust my life to it (not worth taking risks with a motorcycle front brake in my opinion!).

Now don't hate me... I was scratching my head about what to do when I saw the brake I'd recently removed from my 70s Suzuki looking at my from under the bench. It's a full width 8" twin leading shoe drum from a Honda CB77. It would be a serious upgrade over the original half width 5.5" single leading shoe BSA brake.

As I had it to hand it seemed silly to overlook this free safety and performance upgrade option. I have saved the original hub, should I ever decide that originality is important, and made sure to fit the Honda hub in a way that dint require modifying any of the BSA bits should I wan't to put it back at a later date.

So great, I bought a new 19" wm2 rim and spokes to suit the Honda front hub, and repurposed the old front rim, building it onto the rear hub.

The lathe once again came into it's own here, allowing me to make a new axel with the correct metric diameter to fit in the Honda hub bearings with custom spacers, imperial threads and custom sleeve nuts to suit the BSA forks.

Ok, no we're getting somewhere. Time to have the big kids mechano day and start bolting some bits together till we have something that looks like a bike! Was wonderful to see it looking like a bike again rather than just a pile for parts, as it had for the previous year.

[Goldnrust]

Still a long way to go though...

As mentioned on page 1 of this thread, I'd already had the gearbox to bits once, but now had sourced a NOS kickstart pinion gear, here you can see new Vs old.

That was soon installed in the gearbox, and after it was mentioned earlier in this thread that the end float was critical (and also thankfully about the left hand threads!) I did some re-measuring. I reduced the gasket thickness to get the end float of the shafts back into spec.

I cleaned up the clutch, the clutch friction discs were pretty oil soaked, but I felt they cleaned up ok and the clutch seemed ok when I originally got the bike so I presumed would be ok now (foreshadowing... it wasn't!)

The clutch was now assembled, and installed along with a new primary chain and drive chain. I also turned up a chain guard mount / crank case breather / chain oiler from a bit of brass hex, to fit into that threaded boss I repaired on the engine cases.

Whilst on the subject of chains, now seemed as good a time as any to install the magneto and it's drive chain. The mag was making a pretty small spark when spun by hand on the bench, but it was a spark none the less and I'd seen the bike running on this magneto so decided it would be ok for now (foreshadowing... I don't think it is!). I used my dial gauge and got the mag timed to full advance at 1/2" BTDC as specified I the manual.

[Goldnrust]

Handle bars next. This bike uses a very unusual 'split' handle bar, almost like a clip on works on a modern sports bike, there are two separate bars, one for left and one for right.

The bars that came with the bike were bent, and I think possible even not a pair. I did try to bent them into line, but I just couldn't get them to be symmetrical! Of course they are damn near impossible to find secondhand and no one makes reproductions, so time to improvise again. I bought a cheap set of reproduction BSA bars from a B31, cut the middle out of them and made up some solid plugs on the lathe which I welded into them to make a new pair of split bars.

Now I could start running all the control cables. A couple of universal cable kits helped here, and I soldered various ends onto the cables and made it all work with the mis match of parts I had. The only cable I didn't make was the front brake (did I mention not taking chances with brakes!), thankfully I could just use the Honda cable and Suzuki lever.

The fuel tank was fairly grim inside, so that got a POR15 lining. As a poster on this thread pointed out, it's the wrong tank for the year, and should be nickel plated with darker green inlays in the side. I'd like to at least paint it to look correct for 1934, but a job for another day as spring was well on it's way and the road was calling!

I cleaned and rebuilt the carb with new jets and needle, and bought a secondhand choke mechanism to replace the missing one. Next on the list was to solder up some copper fuel and oil lines.

The original front mudguard was truly beyond repair, being twisted and bent and rusted and having been previously bodged several times. I had to cut the hacked up mounting off the forks and turn up a new piece, which was in turn welded back on to the forks and I mounted a smaller more 'racing' inspired front mudguard.

[Goldnrust]

And now we're really getting somewhere. Bolt on the rear mudguard and the seat, and we've got something that is ready for a first start attempt.

Well from the first kick I could feel something was wrong and it was quickly apparent that the clutch was slipping. On a 'pre unit' bike like this, with separate gearbox and engine, the kick is usually attached to the gearbox and relies upon the clutch and then primary chain to transmit it's force to the engine. So most of my effort was just going int slipping the clutch hand the engine wasn't turning over fast enough.

So I stripped the clutch and checked it all appeared to be together right, cleaning it again and had another go. No better. I went through a few rounds of this before deciding to 'rough up' the steel plates a little to give them half a chance of gripping the old friction material. And with that...

https://www.youtube.com/watch?v=SaHiZLQ2hT4

Excellent, and very straight forward. A quick run up the access road behind the house showed some immediate issues though. A few small easily fixed ones, the rear brake rod needed adjusting to put the pedal where I wanted it, bits like that, but 2 big issues. 1. I couldn't get 3rd gear and 2. the oil pump didn't appear to be working. The gear selection turned out to be an easy fix, in all my messing about with the clutch I'd managed to set it up so that the clutch arm now fouled the gear selector and locked me out of 3rd when the clutch was pulled. The oil pump worried me more!

I had pre-primed the bike with oil, as the user manual suggests, and so no harm done. Thankfully the antiquated total loss oiling actually helped me here. Would have wiped the bearings out of a modern engine running it with no oil pump for even a few seconds!

Anyway, looking in the sight glass I had no oil pumping. The pump came apart easily enough, and it was clear that small bits of corrosion from inside the fuel tank had gone through the pump and jammed in some of the tight internal tolerances. With a good clean out and a bit of light sanding to remove some burrs it looked like it would work again.

And it did, I now had a regular 'drip' in the sight glass, excellent. I had ot guess at the amount of oil needed, and massively over estimated to start with!

So feeling like the bike was essentially ready to be ridden I had one last challenge to deal with, electrics. I'd considered just removing the lights and running in a daytime trim but I did want a brake light. I would be going out on 21st century roads and people expect you to have a brake light!

I considered running just a small battery to power a brake light, but then I figured as I did have the charging system on the magneto and from running the bike I confirmed it put out some voltage, so making use of that made sense really. The break through came when I went to buy an LED bulb for the brake light, I did the calculations and realised that LEDs draw so little power that I could fit full modern brightness headlight, tail and brake lights into the original (well reproduction...) light units that came with the bike and still be drawing less than 18w. I also found a tiny little 6v house alarm battery that I could tuck up underneath the fuel tank. A cheap cycle speedo completes the electrics needed.

I've got to say that the headlight impressed me, it's better than my 70s Suzuki for sure, I shall have put an LED bulb in there too I think! And even better, I can confirm with the ammeter than the draw with all the lights on is less than the charging system can put out, so that's good news.

Test ride time, for real, out on the open road... Only once again the clutch is slipping, and slipping worse than ever now. Stripping it down, I'm pretty sure the issue is the old friction material is just shot and seems to leave a greasy residue even though I gave it a thorough cleaning with clutch cleaner. New clutch material is tricky to come by, I found a couple of corners of the internet which said I could order some ,but it was from small stranger websites I'd not heard of before on the other side of the world.

Ultimately I just needed two rings of clutch friction material, so I started looking for other applications that might need a similar thing. I got close when I found various tractor PTOs use similar friction rings, but I didn't find any quite the right dimension. Then in a stroke of pure luck, I came across the fact that the classic Fiat 500 uses a clutch disc of the same size, and even better I own a classic Fiat 500 and have a spare clutch in the shed! Comparing the two they were a perfect match. All I had to do was drill the rivets out to take the friction rings off the centre hub and there would be the parts I needed. Pic to show BSA clutch friction resting on top of Fiat clutch disc for matching size.

It turned out, the spare clutch I had in the shed was probably just as worn and oil soaked as my BSA bits were though (also as asbestosy I'm sure!!), but thankfully Fiat bits are cheap and easy to come by, so I had a new Fiat clutch some next day for £28. Frustratingly this was just 1-2mm larger diameter than my old 1960s Fiat clutch, and whilst in the Fiat this didn't matter, in the BSA this was a problem.

Happily I own a lathe and so, with confidence that the brand new clutch was not asbestos, I quickly popped it on the lathe and turned it down to size. Wit the rivets drilled out I could drop the new friction material into the BSA and cross my fingers.

First kick didn't inspire me with confidence, but I'm pleased to say its just got better and better as it's bed in and I'm now happy to draw a line under this and say the clutch issue is sorted.

Now I could finally go for a ride! All geared up and ready to see what this bike is all about, I made it a whole mile up the road before I noticed the oil pump wasn't pumping again, had a panic and limped back home. It turned out to just be an air bubble in the oil line and nothing to worry about, it had sorted itself by the time I got home.

[Goldnrust]

That mile up the road was enough of a ride to show me several more issues to fix. Several easy adjustments to make, such as tightening up the advance and choke levers, as otherwise every time I hit a bump the choke went on a bit and the ignition retarded a bit!

I also made a new mounting bracket for the front of the seat, that raised the front edge and moved it back a couple of inches. I've seen a wide range of seat mounts when looking for into on these bikes, and given that mine is a bit of a mix and match special, I'm not surprised that the seta and bracket combo it came with wasn't right. Anyway, with the new briquet the riding position was hugely improved.

I also made a quick heat shield for the exhaust, as it was already trying to burn a hole in my leathers!

Ok, try again for a ride! This time I made it about 3 miles, before it started spitting and running worse and worse, kicking out clouds of smoke. I turned for home and tried in vain to make it back, but ultimately was forced to push it home the last couple of miles. After a bit of head scratching I realised that the nipple had come off the choke cable (this is why I didn't trust home made brake cables! haha) and the choke had come back on full, and secondly that the oil pump was adjusted wrong and had filled the bottom of the crank case with far too much oil, which was now being forced past the rings and fouling the plug.

With that sorted I was finally able to take it on a few short local rides which didn't involve break down or pushing home.

https://www.youtube.com/watch?v=DRn7pkbv_og

I'm still working through the teething issues though, and am confident that bike's not running 'right' yet. I knew it would be slow, but currently I'm topped out at around 40mph on the flat most of the time (had it up to 51mph on a downhill with my head on the tank!!!) and at that point I can feel the engine missing and surging with the odd backfire.

I've tried playing with jetting, and having manual control of things like ignition advance and choke does make trouble shooting some tuning issues easier but I'm getting nowhere really. The best results I had were from reducing the plug gap... which leads me to think it might be a magneto issue.

Many magneto issues show up as poor starting, something I'm not suffering with, but it still seems like my mostly likely culprit. So when I've next got some time to tinker in the shed I think I'm going to have to get the magneto apart and see what I can see!

Magnetos are a crazy world of black magic and secrets, or so half the internet would lead me to believe! But if it's already suspect, I figure it's worth me investigating at home before I pay for someone to fix it right!

[courtney]

Thanks for posting your updates.  As a B2 owner myself, I really appreciate you posting all this as it shows what is possible and the ways you've found a way round the issues you've faced.

I think I mentioned earlier in the thread that I considered getting your bike when Andy Tiernan had it for sale, but decided against it. I'm pleased I didn't get it, but by the same token also pleased that you did, and that you're posting progress as it's really interesting to see. Knowing what it was like beforehand,  I wouldn't worry about originality too much; so long as it's on the road and being ridden that's the main thing. 

[Steve.S]

Good to hear of your success. Really nice tickover. If it's backfiring when pulling, this is lightly to be to do with the Maglita. Lucas suggested 0.010" to 0.012" for the points gap.
One of the things to watch out for is the minute spring in the centrifugal cutout. These are made of non magnetic Berrylium, and easily fly off when dismantling. I have a number of them currently orbiting Saturn.
Bearing Part nos. are KLNJ 5/8 and KLNJ 1/2. I would test the length of spark on a spark gap tester.
Regarding your clutch, Saftek at Cleckheaton can make new discs, which are 125 x 90 x 2.4 if you need new ones. I often use a thinner or thicker one behind the clutch drum, to correct chain alignment.
BSA did 2 clutch drums. One had open slots for the steel discs (which let in oil), and the other was closed.
I find it's important to close the oil tap when the bike is not in use, otherwise oil runs into the crankcase and when you start the engine, it blows the oil out of the breather, soaking the clutch. I also find it's important to remember to turn the tap 'on' before starting the engine.
Adjust the oil pump to give a trace of smoke when opening the throttle after a short downhill run, otherwise you will be overoiling and your clutch will start to slip.
Hope this helps.

[Goldnrust]

Well I'm glad it's helped you know you made the right choice Courtney! Thankfully I knew what I was getting myself into, when a dealer says 'it needs a bit of tinkering' you know it's bad. haha.

As a fellow b2 owner, what kind of performance do you think I should expect when it's running right? Do I have unrealistic expectations of mine? I was assuming it would sit at 50ish on the flat and do 55-60 with my head on the tank with a tail wind?

Thanks for the tips Steve. I have fitted an oil tap to my bike, but when it came to me there wasn't one fitted and the clutch was definitely oily!

There is some strangeness around the clutch material sizing. I did order some clutch material from Draganfly, based the part numbers from the 1934 parts book before I dug too deep into it, which was indeed the 125x90mm that you specify, but when I came to fit it, it was much too small. My clutch was ~155x130mm. I found a reference on Cornucopia (I think... or could have been some other small website) for B2 clutch friction material at 155mm OD, but not stock.

I've now had the Maglita essentially completely to bits, though I didn't fully remove the armature from the main body as there's lots of chatter online about 'keepers' and it loosing magnetism by doing that. I gather it applies to some magnetos and not to others, but I was able to see what I thought I needed without removing it, so I didn't risk it!

What I did find was a lot of general dirt build up inside, some of which being metal filings etc, so presume that doesn't help. I also found the that the coil winding wires had been both crimped then soldered to the ring terminals where they attach to the ground/points. One of them I think had a fractured solder joint, so have re-soldered that. The resistances of the coil check out ok.

I tested a theory I found online about using some largish neodymium magnets as a simple way to re-magnetise old magnets, I'm unsure if it did much, but I think it did help a little. The armature seems to 'snap' into discreet positions a little more positively than before.

Point are set at 0.010", maybe I should try 0.012" if I'm running short on other ideas! As far as I can tell, my Maglita is not fitted with a cut out? Unless it's inside the armature itself?

When I next get chance I shall put it back together and see if theres any improvement!

[Steve.S]

On looking at your photo, it's not a B2 clutch. Perhaps of Oriental manufacture, or maybe Fiat?
I seem to remember Lucas recommended a plug gap of 0.015".
Yes, mechanical cutout is in the end of the armature. If you undo the "disc" nut with a peg spanner, remove the end plate and bearing, the cutout is beneath the tufnol and copper discs. Careful with the spring.
I have never known these cutouts to give any trouble.
I just use a couple of spanners either side as keepers. Seems to work OK.
I think your expectations of performance are a little high. In my experience, a Blue Star Junior will do 50mph, perhaps 60 if you don't mind it blowing up, but they do go very well for such a small 90 year old engine.
I would think 45mph, maybe 50 for short bursts, and if it will do that, you have a very good engine. But let's see? I wonder what others think?
Regarding LED headlights, I find they singe your eyebrows when looking at them, but, out on the road, they are quite useless with no concentrated beam at all. All they do is vaguely light up the surrounding country side. This with a new reflector and adjustable focus.