1971 B50T Victor 500 Restoration.

lathejack · Post by **lathejack** » Sun Dec 18, 2016 9:41 pm

I am not sure if I ever felt the need for a B50 before I discovered this site, or if it is a result of visiting this site and forum that has fuelled my desire to obtain an example of BSA's mighty 500 Unit Single.

Anyway, I have finally aquired a B50 Victor. I had set my heart on getting an SS and would have preferred to buy a B50 from a member of this forum. But circumstances at home prevent me from spending time travelling hundreds of miles to view and pickup a bike.

It is a bit of a project that will have an engine strip down, it also requires dating and then registering as it is an import from the good ole USA, Missouri I think.

A set of original type, or very similar, handlebars are one thing on the list of things to obtain.

I would like to get it into mostly original trim, but not simply for the sake of originality. It is simply because I just happen to like the appearance of these bikes just as BSA made them.

The work begins, and hopefully it will be on the roads of Blighty in time for spring next year.

midgie · Post by **midgie** » Sun Dec 18, 2016 9:51 pm

looks good gene,i see what you mean about those bars!

lathejack · Post by **lathejack** » Sun Dec 18, 2016 10:20 pm

Thanks Midgie. At last weeks Autojumble I found plenty of handlebars but nothing that were anything like the originals.

After returning to bikes last year, after a long layoff, with the purchase of two smaller BSA Singles, I am now getting serious with the B50. So I thought it appropriate to finally buy a hydraulic bike lift to make bike restoration more of a pleasure than a chore.

Here is the new bike lift still in its crate after picking it up in the van.

beat · Post by **beat** » Mon Dec 19, 2016 8:39 pm

a next pic of the lift when unfolded please ?
and price ?

is it your christmas gift from your wife ??

beat

lathejack · Post by **lathejack** » Tue Dec 20, 2016 1:04 am

beat wrote:a next pic of the lift when unfolded please ?
and price ?

is it your christmas gift from your wife ??

beat

This had to be a Christmas gift to myself. No amount of hinting or leaving BSA and other motorcycling literature lying about ever results in me receiving any relevant gifts, just usually jumpers and socks.

So I've just been to the workshop and set up the bike stand, and popped the B50 on it. This stand is the smallest and cheapest of four the seller offers, and cost £225 with a lifting capacity of 800LB.

This one is also a scissor lift type, so takes up a little less room. The other three on offer are the usual type that fold down in an arc and cost upto £370 for the top model.

No suprise that it is produced in China, so that makes them affordable, but it looks OK and does its job and is certainly worth the money.

skippy · Post by **skippy** » Tue Dec 20, 2016 6:15 am

I have one aswell

and it saves the back

Barry Creary · Post by **Barry Creary** » Tue Dec 20, 2016 6:42 am

Were did you get yours Doug? And how much was it?

Canberra · Post by **Canberra** » Tue Dec 20, 2016 12:19 pm

I bought one August 2010 @ A$573.50 freight included (unless my records are out) and I believe it was best money I have ever spent. Mine is air/hydraulic operated heavy duty one. They were being sold via Old Bike magazine from someone in Victoria who was importing them. Two of us in ACT bought one each and they were shipped together to save a bit of freight cost.

John

skippy · Post by **skippy** » Tue Dec 20, 2016 10:15 pm

Google it on the internet i found one in Sydney and one in Melbourne Sydney was cheaper but the freight worked out better by buying in Melbourne.
They are about the same price as Johns.

beat · Post by **beat** » Wed Dec 21, 2016 8:06 pm

lathejack · Post by **lathejack** » Sun Dec 25, 2016 2:07 pm

Well I have been finding time during the late night and early hours of the morning to do a bit of dismantling. It was a doddle to lift the engine out, and the new bike lift is proving its worth.

midgie · Post by **midgie** » Sun Dec 25, 2016 7:35 pm

that's what I like to see, no pussy footing about, strip that motor and make sure its all top notch, ready for its next chapter in life. doing it now and yourself will ensure a healthy relationship.

lathejack · Post by **lathejack** » Sun Dec 25, 2016 9:50 pm

Yes I think it is the wise thing to do.

Although it seems good enough to run, this engine is a little low on compression, and it appears to be leaking past the piston and rings rather than the valves. It also has traces of Red Hermetite on the rocker box and cylinder base joint, I hate the vile stuff which has no place on the delicate castings of a motorcycle engine, so will be glad to remove it when the motor is in pieces.

The dealer sticker on the side panel shows that it passed through the hands of Donelson Cycles, the faded part reads St Louis and Flat River. They are still in business.

Maybe I ought to add this B50 and my B25's to the register.

Post by **minetymenace** » Sun Dec 25, 2016 11:59 pm

lathejack, how come you have gone a year and a bit without adding your location to your profile?

lathejack · Post by **lathejack** » Mon Dec 26, 2016 2:10 am

I haven't gone a year and a bit without adding it, my location was on there up until a few days ago. I chose to remove my small town from the location, but the county has disappeared as well.

Not a good idea to make alterations to anything very late at night after a drink, good job I stayed away from the B50 on that night.

Post by **minetymenace** » Mon Dec 26, 2016 10:37 am

wonderful stuff this alcohol, it make me witty, intelligent and very good looking, I'm sure it does the same to all the other B50.org forum members

lathejack · Post by **lathejack** » Mon Dec 26, 2016 11:23 am

As I mentioned, it was a doddle to lift the complete B50 engine out of the frame, with some assistance from my little helper.

midgie · Post by **midgie** » Mon Dec 26, 2016 1:14 pm

i see what you did there gene, a straight swop!

Orange dog · Post by **Orange dog** » Mon Dec 26, 2016 2:51 pm

The jack wil give better economy

beat · Post by **beat** » Mon Dec 26, 2016 8:31 pm

the engine WITH EARS is looking better

lathejack · Post by **lathejack** » Tue Feb 21, 2017 8:30 pm

I have only made a small amount of progress with the B50 in the last couple of months.
I quickly made up an engine stand and did a bit of dismantling.

The motor is as clean as a whistle inside, with no signs that the main crankcases or the inner timing cover have ever been disturbed before.

There is now that nagging question of should I replace the conrod with a Carrillo or other stronger rod while I am inside the motor, seems a shame to risk a blow up on such a beautiful bike.

lathejack · Post by **lathejack** » Tue Feb 21, 2017 8:41 pm

Oh, and my four legged helper lost interest after she realised that the 'Dogs' in the gearbox I had spoken about were not what she was expecting.

midgie · Post by **midgie** » Tue Feb 21, 2017 10:22 pm

dont leave that conrod to chance, its not worth the risk, its bye bye crankcases at least when that lets go.

HPbyStan · Post by **HPbyStan** » Wed Feb 22, 2017 2:44 am

lathejack wrote:Yes I think it is the wise thing to do.

Although it seems good enough to run, this engine is a little low on compression, and it appears to be leaking past the piston and rings rather than the valves. It also has traces of Red Hermetite on the rocker box and cylinder base joint, I hate the vile stuff which has no place on the delicate castings of a motorcycle engine, so will be glad to remove it when the motor is in pieces.

image.jpg
The dealer sticker on the side panel shows that it passed through the hands of Donelson Cycles, the faded part reads St Louis and Flat River. They are still in business.

Maybe I ought to add this B50 and my B25's to the register.

Donelson Cycle still has a large supply of NOS BSA Parts.

lathejack · Post by **lathejack** » Thu Feb 23, 2017 10:58 pm

It would be interesting to know what sort of spares Donelson still have for BSA's.
I am always glad to see these old bike dealers still in business, especially the dealers that supplied an old bike that I own.

Anyway, I have been delving a little further into the B50 motor.
The kickstart quadrant teeth are in excellent condition, but the ratchet gear teeth have the usual wear.
The inner timing cover screws are unmarked, and appear to have never been removed before.

The primary drive internals also appear to be in fine condition, with nothing broken or damaged.
There is provision for lock wiring the clutch spring screws, would a lock wire have originally been fitted by the factory?

The alternator rotor sits proud of the stator, I have seen the same thing on other B50 motors but cannot recall if they were to the same extent as this one.
The magnets are also slightly exposed, and the rotors raised pads with the timing mark have been making light contact with the casting flash around the timing inspection cover screws. A thin gasket was fitted under the primary cover.

The crankshaft does appear to sit slightly over to the drive side, as can be seen it is not quite central to the crankcase joint line, and the gap down each side of the crank webs are quite different.
I assume the B50 crank is anchored to the drive side, with its additional ball race bearing on that side. So maybe some attention is required there.

midgie · Post by **midgie** » Thu Feb 23, 2017 11:25 pm

yes the clutch screws were lockwired from the factory, check the crank spacer has not been omitted(71-1631)

David S · Post by **David S** » Fri Feb 24, 2017 12:01 am

Look at your rotor where the steel sleeve and rotor body meet.They have a tendency too work loose causing the body too slide back and forth and making contact with the timing pointer and inside the primary cover.
I had this happen on my 74 TR5MX and it would knock loudly against the timing pointer when the bike was on the side stand.I bought a new rotor too fix the problem.

David S

lathejack · Post by **lathejack** » Tue Feb 28, 2017 9:39 pm

Yes I will take a closer look at the rotor when I next have the time to fiddle with the engine. I had a rotor come loose from its centre on my electric start T140 thirty years ago, thankfully that was the only Lucas rotor to fail on any of the British bikes I owned back then.

Over the past several months I have seen B50 Pistons for sale that have been described as genuine BSA, but cast inside these Pistons can clearly be seen the AE symbol and Hepolite.

Faintly visible at the bottom of the cylinder liner of my B50 are the words Hepolite and Vacrit. The bore is standard size, and the neatly fitted peg on the lip at the top of the liner suggests this is the one and only originaly fitted liner. The standard size piston is also Hepolite.
So did BSA actually fit Hepolite liners and Pistons originally to the B50?

midgie · Post by **midgie** » Tue Feb 28, 2017 10:10 pm

yes they were hepolite pistons as std fitment, std being part no. 71-2745 or if its an early b50 which I suspect yours is, it could be marked 71-1643.

lathejack · Post by **lathejack** » Tue Feb 28, 2017 11:21 pm

Thanks Midgie
I forgot to mention that the piston part number is, as you suggest, 71/1643.
So I assume that the Hepolite Vacrit cylinder liner is also an original factory fitted item, as it certainly appears to be.

lathejack · Post by **lathejack** » Fri Mar 03, 2017 5:29 pm

One of the original pushrods from my B50 looks a little worse for wear, it clearly hasn't been sat on the cam follower correctly.

I ordered a couple of new ones, but when they turned up I found one of them bent. It also had four small sharp indentations on the bend point, that along with the way it was packed meant it could not have been done by the Postman, so was certainly posted in that condition. The second photo shows the bent new rod against a straight edge.

The dealer quickly posted a replacement without any fuss, but when I checked that one I found the bottom of the rod that sits in the follower had a small chunk of alloy missing.
Again without any fuss he posted another replacement which was fine.

It wasn't until I finally had two new standard pushrods in good condition that it dawned on me. I planned to fit a plate under the cylinder to lower the compression ratio, so I really need two new longer pushrods to allow for that. I would rather buy longer pushrods in preference to pulling off the steel caps to insert a shim.
Oh well, I will look for and order a couple of good quality longer pushrods soon. Or possibly buy a length of suitable Alluminium Alloy or Dural rod to make my own, although it may not be worth it as new pushrods aren't all that expensive.

midgie · Post by **midgie** » Fri Mar 03, 2017 6:45 pm

oh the joy of pattern parts!

lathejack · Post by **lathejack** » Mon Mar 06, 2017 4:06 pm

Oh yes, pattern parts, a never ending source of brief entertainment but eternal dissapointment.

The rear wheel of the B50 is in very good condition, but the drum braking surface was scored and slightly worn.
I had planned to build a simple machine to skim brake drums while in situ on the wheel while rotating on the wheel bearings, complete with tyre if nessesary.
But I spotted a video on YouTube of a virtical mill being used, so I used the same method on my mill after checking all the spokes were properly tensioned.
It only just fitted, and it's a good job I had made and fitted the bronze raiser block on the column a few years ago to lift the mill head.

A single point carbide tipped cutting tool was used. The mill spindle is held stationary, and the wheel is held by its spindle in the locked rotary table.
The wheel is then rotated by hand on its bearings while feeding in the cutting tool.
This is the scored and slightly worn drum before skimming, with an unworn ridge near the outer edge.

The remachined drum surface is an improvement, with an increase of 15 thou on the diameter. I might consider finishing it off with some light grinding, if I can find some suitable tooling lurking in the workshop.

koncretekid · Post by **koncretekid** » Mon Mar 06, 2017 6:14 pm

Looks good. I skimmed my front brake hub in the lathe before lacing. Now I'm trying to figure out a good way of skimming some new brake shoes. I have done some H*nda ones, but they were not full floating so I just mounted the brake plate on a mandrel and lock wired the shoes in position. But with our full floating brake shoes, I can't think of a way to stabilize the shoes in place concentric with the plate or spindle for accurate machining.
Tom

midgie · Post by **midgie** » Mon Mar 06, 2017 9:33 pm

nice job gene.

bacigalupo · Post by **bacigalupo** » Tue Mar 07, 2017 1:34 pm

Hi, just a question about fitting the plate to reduce compression - have you ridden one already, and really think you need it? The reason I ask is based on what I had read I thought the B50 was going to be a real pig to start, and when I bought one I was planning to reduce the compression. In truth I have actually found it reasonably easy to start if the decompression lever is used properly.

Steve

lathejack · Post by **lathejack** » Fri Mar 10, 2017 9:41 pm

I hadn't really thought of easier starting as a reason for fitting a plate to reduce compression. The reason I had in mind was to give the engine an easier lower stressed life, with a softer and milder nature for cruising around country lanes and B roads.

I originally planned to do the same to the two B25's I run, but these still have the standard compression ratio and are not as harsh or unpleasant as I thought they might be. I must admit that the lively nature of them is enjoyable and quite addictive, and the B50 will be even more so.

But my mechanically sympathetic nature means I am still tempted to lower the compression, to give the relatively puny looking bottom end of all these engines less of a pounding.

lathejack · Post by **lathejack** » Fri Apr 14, 2017 1:49 am

I found some small grinding wheels mounted on short 1/4 inch diameter shanks. So I drilled and reamed some longer 1/2 inch diameter bar and Loctited the grinding wheels into them.
Before using them to grind the drum I trued up the grinding wheels with a diamond tipped dresser.

During grinding WD40 was used for lubrication, grinding .001" at a time. The resulting surface finish is vastly superior to that left by the fixed cutting tool. The diameter of the drum is now 19 thou oversize, which is only a fraction more than the diameter left by the wear and scoring caused by the large amount of sand like grit that had found its way inside the drum.

beat · Post by **beat** » Fri Apr 14, 2017 8:21 pm

beat

lathejack · Post by **lathejack** » Sun Apr 16, 2017 4:01 pm

I managed to sneak into the workshop very late last night, and into the early hours of the morning, to finish off dismantling the B50 motor.
I made a clutch hub puller, plus some clutch locking tools and finaly got it all apart to reveal a pristine looking crankshaft.

Despite a bit of wear and tear here and there, the largely undisturbed engine has no damage or bodges from previous amateur mechanics during its 46 year life. If a motor has to be dismantled then at least it's a pleasure to have to work on one like this.

Now I have got this far, and as long as the big end assembly is ok, I may as well spend a few quid and fit a Carrillo.