Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - Calum

Pages: [1] 2 3 ... 8
Which BSA do you ride? / Re: Bsa b31 history
« on: 02 January, 2022, 20:05:19 »
How long ago are we talking? I would think the only way would be through any club(s) or friends who knew them and the bike. I assume you know the registration mark?

Singles / Re: B31 smoking
« on: 02 January, 2022, 13:51:00 »
Bottom banjo removed and drilled to match the top. I managed to remove the bolt once I had loosened the three bolts that hold the front of the inner primary to the crankcase. This gave me just enough room to remove it. I might shorten the bolt slightly when I refit to enable the bolt to be removed in future without having to loosen the primary case again.
The small hole (same as my feed banjos) was around 3/64" but the large was 5/32", if not slightly larger, but I drilled the bottom one to 5/32" to 'match'. I measured them trying different drill bits in which I measured with a micrometer. I had to poke the drill down the main body of the banjo bolt too to open that up to 5/32" as well. I quickly cleaned up the 45 degree sealing faces on the lathe as they were quite stepped and rough feeling. Hopefully it's all sorted now!

Singles / Re: B31 smoking
« on: 31 December, 2021, 00:45:59 »
Well Calum at least youíve found the problem. I must confess that I drilled out the apertures on all those bolts on my B31 as 1/64th seemed to me to be too easy to clog up with a bit of debris. I did open up the lower ones more so. I havenít found it to flood with oil yet or smoke. If it does smoke more as time passes Iíll renew the rocker box ones, they are easy to get to.
I don't suppose it's likely to flood the top as long as the drain holes are considerably larger than the combined area of the supply banjo orifices. I'll remove the drain pipe and drill the bottom banjo out to match the top and see how we get on.

Have you had the head rebuilt. Sounds like wear on the valve guides. Oil in the head sucked into the engine down the side of the inlet valve.
Nope, never had the head off. There's no smoke on the overrun or going down long hills to speak of so I don't think the guides are too bad. I do have some jobs planned for the engine in the future but for now I am just enjoying riding it when I can. Once I finally build my new garage I suspect I will spend a lot more time tinkering...

Singles / Re: B31 smoking
« on: 30 December, 2021, 14:27:39 »
So I finally got around to having a look at this... two rocker feed banjos easily removed, correct small holes. Drain banjo on head is a large hole, drain banjo on crankcase seems to be the small one >:(. Annoyingly the only one that is hard to get to, and I don't think I can quite get to it without removing, or at least loosening, the primary chaincase. Typical! I not long had all the primary stripped when I rebuilt the gearbox, I suppose I should have checked then!

Singles / Re: Any Magneto magicians?
« on: 19 October, 2021, 21:52:24 »
Does the short go away if you back the centre bolt off ever so slightly? It screws into a nut which I believe is encased in plastic/resin to insulate it from the mag body. If this screw is overtightened I believe it can crack the plastic and short across. I only ask about backing it off slightly as a test as I found I had a similar issue on my mag, although with the locktab folded over it did run fine. I couldn't get my head around what was touching where.
I bought one of those timing lights but off someone else on eBay, a little cheaper than the one from 'the magneto guys' but both would be a worthy investment. Very helpful in my diagnosis work on my bike.

The Star and Garter / Re: Grease in gearboxes
« on: 18 October, 2021, 13:06:52 »
In an M20 gearbox the constant gears on the layshaft are fed oil from a drilling in the shaft itself, and hence the gears are lubricated from the inside. I wouldn't trust grease (semi-fluid or otherwise) to make this journey (I am pretty sure it is the layshaft rather than the mainshaft)

The Star and Garter / Re: Headlight underslung pilot
« on: 19 September, 2021, 14:21:35 »
Mine on my '53 B31 is just like the drawing from the manual above. It slides into the clips in the bowl, and the glass lens is held in from the inside by a spring wire pushing it up against the rubber seal.

Singles / Re: BSA M33 500 1955 Engine looses Power after 20 min
« on: 17 September, 2021, 20:19:00 »
Valves not closing properly when hot?

Singles / Re: B31/M20 Gearbox
« on: 17 September, 2021, 20:17:55 »
I rebuilt my plunger B31 box recently and I bought a box for spares (many for the good selector forks) but I did end up using a gear or two out of it. It was stamped M20 on the casing but came disassembled so I can't guarantee it was all correct. I'm pretty sure the gear ratios were identical.

Singles / Re: B31 smoking
« on: 15 September, 2021, 23:53:16 »
Smoke is blue, and smells like burning oil.

Idie, I had heard of that before and it had crossed my mind. Thing is I don't know what size the holes should be, I did read it on here before somewhere but I'll definitely look into it.

Singles / B31 smoking
« on: 15 September, 2021, 19:23:24 »
Hi all

I have been very much enjoying my first summer of BSA ownership. 1953 B31. The gearbox rebuild proved very successful, and the mag rebuild has all but cured my hot running and starting issues. I've just returned from a 420 mile round trip to Suffolk this weekend and the bike never missed a beat. However one problem which seems to be slowly getting worse is the smoking...

It doesn't smoke from cold. It doesn't smoke when under load, nor when on the overrun. But when the engine is hot and I come to a stop at traffic lights or a roundabout it begins to emit a lot of smoke out of the exhaust! It doesn't always do this however, and I haven't worked out of there is a pattern to when it does and doesn't. As I pull away the smoke very soon clears.

My initial thoughts are the top end flooding with oil, and/or the return side of the pump not being able to pump the oil back quick enough after fast running. Oil consumption is generally quite good, so I don't think the rings or the valve guides are too bad; I also think this would cause a constant haze when moving along, but I am open to any suggestions at all!

Singles / Re: bsa b31 plunger MO1L magneto
« on: 15 September, 2021, 19:05:55 »
The explanation with reference to control levers can sometimes be confusing - my girlfriend's NH Ariel has taught wire advance (as does my B31) but her control lever is forwards to tension the cable (I assume the control lever is a right hand one repurposed!)

If it's standard your B31 should be taught wire advance. Looking at the points cover, the control cable should enter the magneto on the right as you look at it. If so, then your control cable needs to be taught (magneto fully advanced) and the points just opening when the engine is at 7/16" before TDC. If you are using a tool that screws into the plug hole to measure the distance, do remember that it is at an angle and not parallel to the piston stroke (as a result you'll be looking for a figure nearer to 15mm rather than 11mm, hope this makes sense)

1953 Plunger B31 here with the same oil tank also

The Star and Garter / Re: Clutch Parts
« on: 15 July, 2021, 18:51:05 »
By the time he got back in touch he had already chucked them! :'(

Oh well, it was a nice offer and I tried!

Singles / Re: Oil on club runs
« on: 15 July, 2021, 18:47:15 »
Hi Callum,

BSAOC Branches are well attended on bikes and some have attendance trophies for branch members.  Some do runs in the evening and weekends and there are the Branch Weekends that include camping and a run out.
There could be other BSA owners and even BSAOC members no too far from you and in the same position.  You could consider sending an invite through this Forum or through The Star to meet up at a local cafe or pub.  You never now you may get a good response.  As you are a younger member you may also attract younger people to BSA ownership - the Club needs them.


Yes indeed, I am all too aware of people in clubs having a grumble but not willing to do anything themselves! If I want meets and runs on weekends I can organise some myself with the support of local sections I am sure, so it wasn't too much of a grumble more an observation.

My two local branches are W Yorks and Manchester but both branch meeting points are 30 miles away or more, which is a long way home when the meetings don't start till 8:30pm and I have to take my bike back to the workshop before driving home with work starting at 7:30am the next morning (currently waiting on planning permission to build my modest garage at home, and the living room is already occupied by my girlfriend's Ariel NH!)

To be honest I haven't looked too hard at local branch events recently as I have been quite busy so will take another look and make the effort!

Apologies for the thread hijack

Pages: [1] 2 3 ... 8