Search found 936 matches

by BSA_WM20
Thu Feb 11, 2021 11:42 pm
Forum: Tech
Topic: B50 hydraulic drum brake
Replies: 53
Views: 3199

Re: B50 hydraulic drum brake

The original backing plate is an Al-Si-Cu die casting, which from memory was BS 401 in the old system. This alloy age hardens and becomes substantially more brittle over time. This should not be a problem is the loads are applied dead square to the casting as all of the load is compressive. But wear...
by BSA_WM20
Thu Feb 11, 2021 11:23 pm
Forum: Tech
Topic: B50 ignition switch
Replies: 12
Views: 706

Re: B50 ignition switch

Parking lights are important in places like the UK were back roads are barely wide enough for a motorcycle let alone a car , truck or tractor. Down here where lad was not as limited, roads are generally wider and there is sufficient verge to park off the trafficable section of the road. Thus parking...
by BSA_WM20
Fri Feb 05, 2021 11:19 pm
Forum: Tech
Topic: B50 hydraulic drum brake
Replies: 53
Views: 3199

Re: B50 hydraulic drum brake

Way back when I had long hair & a full set of teeth engine braking was fine. Even in a big city like Sydney, one vehicle a minute was considered to be congestion. Now days when 1 vehicle a micro second is considered normal flowing traffic & computer controlled acceleration & braking has the car in f...
by BSA_WM20
Tue Feb 02, 2021 11:17 am
Forum: Tech
Topic: B50 hydraulic drum brake
Replies: 53
Views: 3199

Re: B50 hydraulic drum brake

Yes ,
But did they use the same backing plate all season or regularly swap it over like most parts on a race bike ?
by BSA_WM20
Wed Jan 27, 2021 10:55 am
Forum: Tech
Topic: B44 piston into a B40
Replies: 2
Views: 389

Re: B44 piston into a B40

Depends if you like a nice soft 6.5:1compression ratio
The B 40 is a B 25 with a bigger bore
The B 44 is a B 40 with a longer stroke thus the piston is shorter pin to crown.
by BSA_WM20
Mon Jan 25, 2021 11:51 am
Forum: Tech
Topic: Piston ring gap
Replies: 6
Views: 521

Re: Piston ring gap

YES Total Seal use a wider gap on the top ring in order to make the 2nd ring work properly As they described it to me when I questioned it. They consider the top ring as nothing more than a fire ring to take the heat & shock loading from the exploding chare The 2nd ring provides the seal if it can g...
by BSA_WM20
Fri Jan 22, 2021 9:37 am
Forum: Tech
Topic: Piston ring gap
Replies: 6
Views: 521

Re: Piston ring gap

And if using the gapless rings, the gapless one goes in the 2nd position.
by BSA_WM20
Sun Jan 17, 2021 10:23 am
Forum: Tech
Topic: Stripped thread - tank rack
Replies: 4
Views: 453

Re: Stripped thread - tank rack

0 ) make sure the hole is KLEAN before you start and I mean KLEAN with a capital K It helps a lot if you get a fine center punch and put a few punches in the side of the hole to give the goop some better purchase. They do nit need to be deep enough to plant potatoes in . When you fir the rack fit th...
by BSA_WM20
Sun Jan 17, 2021 10:18 am
Forum: Tech
Topic: wet sumping valve
Replies: 5
Views: 584

Re: wet sumping valve

Further to Kommandos words of warning. None of them work long term for the same reason the exact same set up already fitted to your bike by the factory fails. The spring is held open every second the engine is running and every second it is having hot oil flowing over it. Over time the spring gets b...
by BSA_WM20
Mon Jan 11, 2021 12:04 pm
Forum: Tech
Topic: auto decompressor/valve lifter ???
Replies: 25
Views: 1818

Re: auto decompressor/valve lifter ???

And whatKommando failed to mention is if the whole thing does not fly apart and trash the engine then the gap in the cam trashes the cam follower. Also found on the 31 & 33 series. Same item used by Kokler bit they use a substantially bigger cam . I rather like a manual decompressor because only YOU...
by BSA_WM20
Wed Jan 06, 2021 9:58 am
Forum: Tech
Topic: Rocker return spring??
Replies: 7
Views: 717

Re: Rocker return spring??

Page numbers did not change with the various reprints
My copy is the 65 reprint and it is in chapter III page 38
by BSA_WM20
Tue Jan 05, 2021 1:52 pm
Forum: Tech
Topic: Rocker return spring??
Replies: 7
Views: 717

Re: Rocker return spring??

This was back in the 50's & 60's when you used whatever you could get cheap.
Before clubmans racing became the provinance of millonairs.
Every one had a box full of wire coat hangers from the dry cleaners.
by BSA_WM20
Mon Jan 04, 2021 7:18 am
Forum: Tech
Topic: Rocker return spring??
Replies: 7
Views: 717

Re: Rocker return spring??

Don't know about that but the old timers who raced Goldies down here used to wing clock springs from old coat hangers & take them to get heat treated into springs to keep the rockers on GS heads in contact with the pushrod. Apparently you were good to 9000 rpm before the rockers would jump off the p...
by BSA_WM20
Sat Jan 02, 2021 9:36 am
Forum: Tech
Topic: auto decompressor/valve lifter ???
Replies: 25
Views: 1818

Re: auto decompressor/valve lifter ???

Probably the same as every H*nda stationary engine
A pivot that pokes through 1/2 the width of the cam that springs out of the way due to centrifugal forces
by BSA_WM20
Thu Dec 10, 2020 12:11 pm
Forum: Tech
Topic: Which Spark Plug?
Replies: 16
Views: 1396

Re: Which Spark Plug?

Nothing really to do with the engine temperature or the level of tune.

It is all about keeping the plug clean.
If carbon is being deposited on the plug then it is too cold
If the insulator nose is bright white or melting then it is too hot.
by BSA_WM20
Sun Nov 29, 2020 11:33 am
Forum: Tech
Topic: Brake master cylinder.
Replies: 7
Views: 1059

Re: Brake master cylinder.

Have you got a fork brace lined up as part of the upgrade.
Even with the comicals B50 front ends tended to walk under heavy braking.
by BSA_WM20
Tue Nov 17, 2020 11:42 am
Forum: Tech
Topic: Fitting Allen screws to rocker box on B50.
Replies: 35
Views: 7280

Re: Fitting Allen screws to rocker box on B50.

The problem with using coarse threads in the head is there is insufficient metal in the floor over the push rod tube for a coarse thread. Ideally you should have a minimum of 3 full turns of thread on any fastener. More in soft materials like aluminium. If you think this is BS then count the threads...
by BSA_WM20
Fri Nov 13, 2020 8:56 am
Forum: Tech
Topic: b40 engine weight ???????
Replies: 4
Views: 876

Re: b40 engine weight ???????

More like 10 kg heavier as it has a real flywheel as well
by BSA_WM20
Sat Oct 31, 2020 7:54 am
Forum: Tech
Topic: Rebuild Compression
Replies: 26
Views: 2719

Re: Rebuild Compression

The standard test is to see if you can leave a cresent indentation in the copper by rolling your thumb nail into it .

And hats off to you sir,
A lot braver man that I and SWMBO lives 1300 km Away
by BSA_WM20
Fri Oct 30, 2020 12:37 pm
Forum: Tech
Topic: Rebuild Compression
Replies: 26
Views: 2719

Re: Rebuild Compression

And while we are myth busting 1) wire brushing will not work harden the copper unless you are really laying into it hard enough to see flow lines starting to happen on the surface. 2) cleaning with steel wool will also not work harden the surface of the copper 3) chemical cleaning will also not affe...
by BSA_WM20
Fri Oct 30, 2020 12:26 pm
Forum: Tech
Topic: Rebuild Compression
Replies: 26
Views: 2719

Re: Rebuild Compression

Oh, another thing, when you roasted the head gasket. Did you dunk the cherry red metal in a bucket of ice water to really soften up the copper? This is a furfy . Slow cooling , quenching makes absolutely no difference what so ever Lots of people like to dunk primarily to blast off the oxide layer w...
by BSA_WM20
Wed Oct 21, 2020 11:20 am
Forum: Tech
Topic: Ok..now its got me mad..spark plug
Replies: 11
Views: 1690

Re: Ok..now its got me mad..spark plug

Try starving the engine off when you have finished for the day. I have a problem with the non- volatile fraction of what passes for fuel now days. That is the TARs that even a computer controlled fuel injected engine can not burn which is why we have after burners fitted to the exhaust , cunningly c...
by BSA_WM20
Fri Oct 09, 2020 12:09 pm
Forum: Tech
Topic: 1966 Bsa b44 enduro
Replies: 3
Views: 924

Re: 1966 Bsa b44 enduro

They would be the seat mounts for the dual seal not fitted to the enduro .
by BSA_WM20
Sat Sep 26, 2020 5:42 am
Forum: Tech
Topic: Rickman Framed B44
Replies: 11
Views: 1614

Re: Rickman Framed B44

You are going to have trouble doing that freehand .
The heat in an arc is a lot harder to control than the heat in a gas flame
by BSA_WM20
Wed Sep 23, 2020 10:54 am
Forum: Tech
Topic: Chinese Carburetor
Replies: 4
Views: 986

Re: Chinese Carburetor

And to add my 2 bobs worth I fix small engines now days for a living Regularly I get a problem child into the workshop where the owners has fitted a mass of cheap parts they bought off evilbay or amazon. I have found carb with no air passage drillings , no float needes , no fuel hole, no vent hole n...
by BSA_WM20
Wed Sep 02, 2020 1:18 pm
Forum: Tech
Topic: B25SS exhaust pipe
Replies: 11
Views: 1950

Re: B25SS exhaust pipe

HE makes custom pipes as well.
by BSA_WM20
Sat Aug 29, 2020 11:40 am
Forum: Tech
Topic: B25SS exhaust pipe
Replies: 11
Views: 1950

Re: B25SS exhaust pipe

I'd agree with Jeff K and sympathise with the purchaser. Who ever is fabricating those pipes needs to invest in a 1/2" or more smaller center line radius tooling. Very easy pipe to make; would be good if they were made from 409 or 304 stainless or even titanium. Barry at Overlander makes all his pi...
by BSA_WM20
Sun Aug 23, 2020 10:29 am
Forum: Tech
Topic: Oil leak(s) b50
Replies: 11
Views: 1654

Re: Oil leak(s) b50

Trevor I’ve had a search on eBay for bunn breather with no results do you have a link. Rex did a batch about 5 years ago and has not made another as he is no longer interested in motorcycling. The company was Carrel industries from memory If you want to buy the business from him then his address is...
by BSA_WM20
Thu Aug 20, 2020 9:41 am
Forum: Tech
Topic: Oil leak(s) b50
Replies: 11
Views: 1654

Re: Oil leak(s) b50

I still have a Rex Bunn on my B50 with no leaking I wonder how Rex is going haven’t seen anything from him for a while. He has given up motorcycling all together and ended up selling all of his surplus stuff to Stuart Penhall . Stuarts son has been selling the cashe off on evilbay for a long while....
by BSA_WM20
Thu Aug 20, 2020 9:37 am
Forum: Tech
Topic: Oil leak(s) b50
Replies: 11
Views: 1654

Re: Oil leak(s) b50

The O ring goes on the crankcase mouth Oil passes around the threads up the hole in the barrel for the stud to pass through then out from under the head bolts totally bypassing any gasket. You can spotface the head if you like and put a copper washer under the steel one and replace the nut with an a...
by BSA_WM20
Tue Aug 18, 2020 9:44 am
Forum: Tech
Topic: Oil leak(s) b50
Replies: 11
Views: 1654

Re: Oil leak(s) b50

The usual fix is to put a slight countersink in the crankcase around the stud then an O ring to seal off the stud
It is crankcase fume being forced up the bolt hole.
If your name is Rex Bunn you now spend 5 years researching breathing and design a new crankcase breather system
by BSA_WM20
Sat Aug 01, 2020 12:52 pm
Forum: Tech
Topic: Speedometer Cable Lube?
Replies: 3
Views: 687

Re: Speedometer Cable Lube?

The only thing I lube any cable, throttle, clutch, brake or speedo is Tri-Lube dry cable lubricant . You get it from push bike shops being a British Bike rider you might need to take some smelling salts & a fried to help you recover when they tell you the price but a little goes a very Looooooog way...
by BSA_WM20
Wed Jun 03, 2020 9:52 am
Forum: Tech
Topic: B40 triple clamp material
Replies: 13
Views: 2485

Re: B40 triple clamp material

Well to keep it on / off topic.
THe A65L did around 150,000 miles without any problems from the wire mounted headlight.
The B 50 T used to eat a set every year or so .
by BSA_WM20
Sat May 16, 2020 9:09 am
Forum: Tech
Topic: Blown main fuse
Replies: 4
Views: 1221

Re: Blown main fuse

I had this happen regularly on my B 50 T Seemed to be quite random . Ended up being the steel side cover having cut through the gromets managed to touch the neg terminal on the battery and poof, no more fuse . Took a long while to find it. The A 65 L had one of those idiot in line stop switches on t...
by BSA_WM20
Fri May 08, 2020 7:55 am
Forum: Tech
Topic: Electronic box mounts
Replies: 4
Views: 1330

Re: Electronic box mounts

Depending upon the price I will take a UK prepaid box full which from memory is about 1kg
Otherwise the freight gets silly
by BSA_WM20
Tue May 05, 2020 9:54 am
Forum: Off topic
Topic: Any part of the old BSA Company still around?
Replies: 3
Views: 1590

Re: Any part of the old BSA Company still around?

BSA had a lot of subsiduries that traded under their own name Churchill Engineering is still there as is Bertley Engineering. 'Jessops & Savelle steel both got sucked into the British Steel mergers under the Thatcher government and are now owned by one of the Indian conglomerates, can't remember the...
by BSA_WM20
Mon Apr 27, 2020 4:20 pm
Forum: Tech
Topic: 1969 oil tanks diferences
Replies: 6
Views: 1404

Re: 1969 oil tanks diferences

Kommando is once again correct.
The long neck will dig into your thigh if you like to ride with your knees in ( the proper way )
I rode a B40 GA for 15 years that has the long neck on it and had a perminent bruise from the filler cap
by BSA_WM20
Tue Apr 07, 2020 10:47 am
Forum: Project bikes
Topic: Converting a B50 to wet sump. (aka Boris Johnson)
Replies: 102
Views: 17152

Re: Converting a B50 to wet sump.

BSA gave up making wet sumps around 1936 from memory which the release of the new B group. They did this for very good reasons What do you imagine their reasoning was? Viscous drag for starters both on start up and while running. Remember your car has an external flywheel behind the crank & a small...
by BSA_WM20
Mon Apr 06, 2020 11:17 am
Forum: Project bikes
Topic: Converting a B50 to wet sump. (aka Boris Johnson)
Replies: 102
Views: 17152

Re: Converting a B50 to wet sump.

BSA gave up making wet sumps around 1936 from memory which the release of the new B group.
They did this for very good reasons
by BSA_WM20
Fri Apr 03, 2020 5:54 am
Forum: Parts & Bikes wanted
Topic: Brad Jones looking for B25T
Replies: 4
Views: 1408

Re: Brad Jones looking for B25T

Wasn't thinking.
Should have deleted it & added it as jpeg so it can't be vacuumed up by web crawlers.
I wondered why we had not seen nor heard from him for a long while