BSA 650L


Over 1,000 Posts
Sit on the bike, look to your left and then look down at the front motor mount lugs. The VIN should be stamped on the flat spot on the lug. It may be stamped very lightly and covered by paint.


Been Around the Block
So here's my current thinking on the Lightning project.

My goal is the minimum restore, get her running and roadworthy. To that end, and in no particular order:

1. Top end service, check valve timing and give it a general once over. I don't want to ask any questions I might not like the answer to, so I won't strip the engine down right now.I'll swap out the valve springs in any case, but won't go further than I obviously need to when the head's open.

My only uncertainly is the oil pump. I'm OCD about oil, and am thinking about the SRM oil pump. Can I install that with the engine still in the frame?

2. Wiring. I have zero confidence in 52 year old wiring, so I'm going to rewire it. I'll also make it 12V negative earth like the good Lord intended, and fit electronic ignition. I'm leaning towards Pazon but would be open to advice and experience from the forum.I'll need to add indicators cos I don't like not having them, and rebuild the headlamp shell and idiot light. Rather tha upgrade the alternator I'll use LED bulbs to minimize the draw from the system

3. I'm going to rebuild the front forks, just so I know what I've got. The forks are Betor units, and I don't know much about them so I want to have a good look and see what I've got.

4. I'll also rebuild both brakes and just see what condition the wheels are in. I'll swap out bearings as a matter of course.

5. The frame is in good shape, and doesn't need repainting, so I'll restrict myself to pulling the swing arm and changing the bearings.

6. New Hagon shocks, new tires, new exhaust, new handlebars.

7. General clean up and paint with VHT Gloss epoxy paint.

Any thoughts, experiences, suggestions?


Been Around the Block
Ah, British bikes...they put the side stand on the left, and the oil tank drain hole on the side at the right, so you have to lean the bike over and hold it the other way to the side stand in order to get all the oil out. Love it.

That gripe aside, the 'filter', if I can call it that looked fairly clean:


and it was time to get the bike up on the ramp. It doesn't have a center stand, so I just used a scissor jack at the rear of the frame, plus a wheel chock and some tie-downs to keep it all solid:




Here's a better close-up of the oily port:

and the dry one:

Current plan is get the top off and have a good look, then get the barrels off and have a good look, and then get the rest of the engine out of the frame for rebuilding. Stay tuned!


Been Around the Block
Wife was out with her boozy mates tonight so I got a little Bitsa time. Took off the air filters and carbs:


On the RHS the bolts were so tight that the stud unscrewed from the cylinder head instead:

Red loctite on the carb mounting bolts:

LHS one came off without any trouble but I noticed its tickler is gone:

and the throttle cable has corroded solidly into the carb slide:

Soaked it in WD40 and left it for another day.

Sump plate came off:

and judging from the sheer volume of oil, I'd say it was wet-sumping. Seriously, more came out the sump than the tank! Filter looked OK, as did the oil itself:


Over 10,000 Posts
That's probably a good thing that it wet sumped and maybe protected the bottom end from too much rust.

When you clean up the carbs and refit them, try to reface the mounting flange and use lock nuts and don't tighten them down too much. Those crabs tend to bow when the nuts are tightened and then they leak air.


Been Around the Block
So today was mainly about removing all the stuff so I can get clear access to the engine. My plan now is to do a full rebuild of the motor, so it has to come out of the frame, and a bunch of stuff has to move to allow that. The good news is that soaking the bike in WD40 when I first got it, and a few more times since, seems to have worked well, and I had no problems with undoing any bolts. Yet.

Anyway, off with all this:


Mr. Frodo! Thaat's a left-'anded Whitworth right there!

and off with this:

Lets the whole brake chain come off as a piece. Interestingly, there seems to be no bolt for this to screw into, and it seems to have been held in place by the rust. Held quite well, I might add.

Then another left'aanded Whitworth:

Removing the clutch inspection cover revealed some fine swarf-like material


Urgh. With the footpeg off, I could see a crack in the sidecover that had been masked by the footpeg:

The bigger ding I could see before, and I'm OK with, but I don't like the crack. Getting the cover off shows it's been supported from the rear by some JB Weld or similar:

Would welcome opinions on whether this is serviceable or scrap.


Been Around the Block
Looking at the clutch, it seems that the clutch springs were not done up with the correct tool, or even a chisel with a divot ground in it

The screws are flush with where you could get it with an ordinary screwdriver, or a smaller one used on just one side with a hammer used to drift the screw round. Oh well. Everything else look OK:

On the other side, the timing cover came off easily

and looks fine at first glance. I pulled out the bodged wiring loom, ignition coils and mounting brackets, and removed all the oil lines from the tank. Then removed the screws holding the toolholder in:

Both the oil tank and toolholder are now free, but will not come out until I remove the rear fender I think. Then, 'twas beer o'clock and tools were downed for the day


Been Around the Block
So I got the rocker cover off today




Also took off the points to show the advance/retard

Not much to report, looks clean enough. In other news, the middle engine mounting bolt is MIA:


Been Around the Block
OK chaps, I got the inner timing cover off with no real issues, but one oddity I wasn't expecting. The back of the advance/retard mechanism just doesn't want to be removed:

Once the inner cover was off, the intermediate gear is connected to it:


How do I separate them? Just a puller, or something more subtle?

Also, here's some shots of the gear side now the cover is off:





Some fairly thick, gloopy gearbox oil there.


Been Around the Block
OK, so here's where I got to today. Alternator and clutch are now full off, with no major issues. Hand pressure with a pickle fork got the rotor off:

and here's the removed assembly






irk miller

You've been mostly-dead all day.
Never occurred to me to use a pickle fork for something like this. No marring?


Been Around the Block
None. It was very gentle, leveraging off the case, just a small push with my hand and the rotor shifted. I wouldn't have used more force for fear of damaging the crankcase, but it worked just fine


"You Meet the Nicest People on a Honda"
FUN! This is the shit I like to do... I need another project bike to refurb the engine on.... Maybe I can score enough parts from all my triumph friends to cobble together a bobber or sorts.


Been Around the Block
Well, end of phase 1 today: engine is out of the frame:





Now I have removed all the case connecting bolts, but it looks to have been stuck together with loads of sealant, and it has resisted moderate attempts to split the cases. Before I get medieval on it, any advice for case splitting?


Been Around the Block
Finished off dismantling the frame today. Or almost.

Rear wheel came off just fine. My bike has no speedo drive, just a spacer and a cap. More evidence (if it were needed) that's she's mainly been a racer:


Rear wheel came off just fine, as did the drive wheel:



Front wheel came off as usual, and the betor forks my bike has just came smoothly out of the triple clamps without fuss:



Disassembling the top clamp showed that the triple tree runs of open ball bearings in races:




Oh well. Will look into replacing these with proper bearings in due course.

The biggest cause of frustration today was getting the swing arm pivot spindle out, and it still is. I may have to get medieval on it tomorrow. We'll see what tomorrow brings. But the frame is now completely disassembled except for the swing arm, which is clinging on for dear life.


Over 10,000 Posts
Lots of us replace perfectly acceptable crowded ball bearings (cup and cone) with taper rollers, but even modern high performance bikes use the same old design. The only difference is that modern balls are typically spaced evenly with a plastic cage.

If the cup or cone are full of indents, they need to be replaced, but if not, grease it all up and fit new 1/4" balls and you'll be fine.

BTW that's a QD rear hub with sprocket and brake drum on the same side to make wheel changes quicker in a race.


Been Around the Block
Thanks! Got the swing arm out in the end, but will need a new spindle and bushings. Got really medieval on it, with fire and fury...

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