Category Archives: Panther

Panther motorcycle restoration

Getting Tooled Up.

Missing from the bike when I got her were the rear chainguard and the toolboxes.

The chainguard has been replaced with a modified guard from another bike, a Velo, so that just leaves the toolboxes.

There are two of these, one mounted either side of the rear mudguard and they are mirror images of each other, shaped like a truncated triangle but having a curved top to match the curve of the mudguard, as in this catalogue picture.

1937 Catalogue Picture

1937 Catalogue Picture

The possibility of finding a pair of these is so slim as to be discounted so it meantfabricating them, either in metal or in fibre-glass and as by no stretch of the imagination am I a tinsmith there was really only the second option viable.

This meant making up a dummy box or “plug” to make a mould from and as I have an alloy template of the shape and some reasonable photographs that was not too difficult.

To make the plug I cut out a front and a back pieces from 10mm plywood, they were cut as a pair and the alloy template screwed onto them.

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Template screwed onto 10mm plywood

They were then attacked with a coping saw

  PIC DSC01964

Rough cut to shape with a coping saw.

to get them near to size and finally sanded to shape.

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Sanded to final shape

A set of locating holes were bored through the pair and the screws removed.

The end plates needed to be spaced apart to make the plug so lengths of tightly fitting dowel were pressed into these holes.

3mm plywood was next used to close off the sides between the dowels and then body filler added to get near the required contours

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Woodwork completed and adding filler. The screws are to key the filler in place

The filler was added in several layers until it was a little proud of the side pieces and allowed to harden before being sanded down to give the final shape.

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Plug being sanded to shape, the locating dowels can readily be seen

With the centre piece of the plug being completed it was treated with wax polish and then the next thing was to fit a pair of side cheeks.

These were cut from a piece of MDF board and their surface well treated with wax polish before they were screwed onto the sides of the centre piece.

DSC01967

Plug core being fitted to cheek

 

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The completed plug

 

 

TO BE CONTINUED

Let There Be Light.

Last time I went to go out on the Pussy I found the battery was nearly flat.

Due to the risk of interfering little fingers switching the lights on in the garage I always disconnect the battery when I park her up, there’s a quick-connect there for this very purpose, so I realised something was wrong.

Once she was fired up I switched the lights on and revved her up, sure enough the ammeter showed a steady discharge and the lights did not brighten up, the dynamo wasn’t charging!.

So it was down to the garage today with meter and tools.

Main suspect was the dynamo itself, it being both elderly and a product of the Prince of Darkness.

First thing was to uncouple the drive, this meant removing the dynamo chaincase and then the dynamo itself, not difficult but fiddly, the electrical disconnect was easy, just take out the lock-screw and plate, pull out the  two “plug” connectors and I soon had the dynamo on the bench.

First to be checked were the brushes had they stuck in their holders?, were they contacting the commutator?, what was their insulation like?, how about their connections? All seemed well here.

Next I put a piece of paper between each brush and the commutator and tried the meter across them, maximum ohms as it should be, check each brush to earth, one was virtually nil ohms and the other maximum, again as it should be, removed the pieces of paper so the brushes were in contact with the commutator and measured across the brushes, a low ohms reading so that’s OK, try two or three other positions round the commutator and the readings were the same so that side of the dynamo seemed OK.

This left the field coil so I put the meter across it and found a low ohms reading, as it should be, so I tried the meter across the coil to earth, found the same low reading and promptly thought I’d found the fault in the coil shorting to earth.

I then realised that one end of the coil was MEANT to be connected to earth so I disconnected that end, tried again and got a maximum reading so the coil checked out.

Since the dynamo checked out electrically I next tried a quick and dirty check, if you connect a battery across a dynamo it will run as a motor, this is not an absolute check, since while if it doesn’t motor then it’s definitely  U/S  the fact it will motor is not a guarantee of it being OK, just an indication that it probably is .

To motor a LUCAS dynamo you need to connect the “D” and the  “F” terminals in the dynamo together  and connect them to the live side of your battery, connect the other side of the battery to the dynamo casing and it should spin over and mine did, so, taking the electrical checks along with the dynamo motoring the dynamo seemed OK.

Next to check was the regulator and to access this meant the saddle had to come off.

So it was unbolt the saddle springs, remove the front pivot bolt and lift it away, much easier to say than to do!

The regulator is bolted to the saddle support bracket so that was next and I had the regulator loose in my hand.

The fault was immediately apparent, a broken wire!.

The brown lead to the “A” terminal had broken just where the inner wire leaves the insulation, it was being held in place by the harness but was not making a connection.

The “A” lead is the one taking power from the regulator forward to the ammeter and hence the main switch and from there back to the battery so it’s not surprising the battery was flat.

The connection was soon remade and then everything had to go back together again.

As a point of information, the connections to the regulator are usually in the order “F”  “A”   “D”  “E”, that’s Field, on Panther that’s the green lead, “A” goes to the Ammeter and gets the brown lead, “D” goes to the Dynamo and is the yellow lead and the black Earth lead goes to “E”.

Some of the late pattern post-war regulators had them in the order “D”  “E” “A”  “F” but a quick look at the wire colours tells you, the only ones I’ve seen like this were the late pattern rubber mounted regulators with the crimped on aluminium casing.

Fork It

I’ve now got some 300 miles up on the old girl and it’s time to make the initial running adjustments, a 300 mile service as it were, but I’ll leave the initial oil change till just before I put her away for the winter or 500 miles, whichever comes sooner.

Most of these are obvious ones, valve clearances, chain adjustments, cable free play and such, but one set are not, the front forks.

After the Second War there was an almost universal adoption of the hydraulicly damped telescopic fork for front suspension on bikes.

Previously there had been several options but probably the most common was the “parallel ruler” type or “girder fork”.

In the late 1930’s Panther did not make their own forks but bought them in from “Webb”, probably the best known of the proprietary manufacturers. For the Model 100 they used Webbs “HeavyWeight” fork, similar to that pictured below which shows the fork as intended for use on a Velocette motorcycle. This is taken from the “Webb” catalogue of the time, which I have lifted from the “Velobanjogent” website HERE

Webb Girders

Webb Girder Forks

This pivots on four spindles, two running in the yokes and two in the fork girder, the spindles being joined by pairs of links, the illustration below shows the layout, here in a different fork model and again taken from the same catalogue.

Webb Links Set Up

Webb Links Set Up

What needs to be adjusted is the freeplay of the spindles, if it is too tight the links are pulled tight against the yoke and the fork girder and the fork becomes locked up but if too slack then the girder can move side to side to the detriment of the handling.

As you can see the right link has the spindle threaded into it while the left one is plain and locks up against a shoulder on the spindle, adjustment is by threading the spindle further into or out off the right link.

To gauge the free play there are a pair of knurled washers at “C” and “D”. Adjustment is correct when one of these is held firm by the link but the other can be rotated, that means there is minimal free play in the joint.

When I rebuilt the old lady I had the forks refurbished by Percival and Webb down in Birmingham. However now they have a few miles on them things have settled in and they now need adjustment, a bit of excessive free play having appeared.

To make the adjustment one end of the spindle is squared to take a spanner, however I prefer to use a tap wrench here as I find it gives better control.

Spindle Adjustment

Adjusting top rear spindle

The adjustment technique is not quite as obvious as it seems, first you slack off both the locknuts “A” and “B” and make your adjustment of the spindle.

You the tighten locknut “B” followed by “A” and then you check the play, if it’s right all well and good, if not try again. It’s a bit fiddly but you soon get the feel for it.

If you try to set the play without retightening “B” each time, and then locking it up afterwards you’ll find things set too tight because when you pull up on “B” it moves the link a fraction inwards on the threads by enough to take out the freeplay you have just so carefully set! Experience speaking here!.

Once you have one spindle set then you move onto the next until you have all four set.

Since the spindles are working in plain bushes you need to keep them well lubricated, this means regular greasing with the inevitable result that there is excess grease appearing at the links that you need to clean up, don’t just leave it as there is a friction damper as part of the lower right link and you definitely do not want any grease to find its way in there!.

Back in the day a standard part of the manufacturers tool kit that was supplied with the bike was a small grease gun, about 6 inches long, intended for this very job.

Basket Case

While doing the clutch recork I noticed that the bottom plain plate of the clutch was sitting a bit too deep into the clutch’s outer‭ “‬basket‭”‬,‭ ‬so that the‭  ‬innermost insert plate was having its tongues bottom-out in the basket cut-aways.

This meant that the bottom insert plate was only gripping on one side, also because there was no “sandwich effect” with the insert plate between a pair of plain plates, the grip on the upper side of that plate was impared. This means that the clutch had lost‭ between ‬1/6 and 1/3 of its gripping area.

Bottom Plate

This is the bottom insert plate. This picture is of the upper side and you can see that the inserts have been pressed flush with the plate. There are also scuff marks where the metal of the plate has been rubbing against the next, plain, plate.

It also said that the inner drum needed a thicker distance-piece between it and the clutch‭ be‬aring cheekpiece.

To sort this out I put a steel-rule through the cut-aways‭ ‬in the basket and across the bottom plate,‭ ‬then measured how far that plate was clear of the bottom of the rule.

The inner drum was then removed and the thickness of the existing spacer measured,‭ ‬this dimension was added‭  ‬to the plate clearance and gave the size of spacer required.

All that then needed to be done was chuck up a bit of round bar in the lathe and turn up and part-off a new distance piece of the correct size.

Once this had been fitted,‭ ‬the position of the bottom plate was again checked,‭ ‬and,‭ ‬once I was satisfied then the clutch centre nut was tightened down and locked in place.

However this changed the distance between the clutch operating lever on the gearbox and the clutch backplate enough to take it beyond the available so a new clutch push-rod needed to be made up, longer than the previous by the additional thickness of the spacer.

Now that the clutch has been re-corked I have to expect that the plates will settle in a bit initially,‭ ‬so I’ll have to look to a clutch re-adjustment‭  ‬after a few miles of bedding in and hopefully that will be the clutch set up for the near future‭!‬.

Getting a Grip

Having replaced the clutch springs a few weeks ago I’ve now some more miles up on the old girl and the clutch is not standing up to the strain.

I’ve more or less expected this since these older Panthers have a cork lined clutch and the plates in mine have seen an unknown amount of use.

They are beginning to slip a bit when kicking the bike over from cold and this of course will only get worse, so I’ve got to do something about it.

In among my Panther swag is a bag of the cork inserts.

wornplate + inserts

A worn plate and some new inserts

and I’d just have to fit them the insert plates, The tricky bit is to get them evenly inserted, I can’t just push them in and hope for the best so I had to make up a jig of some sort.

Since the inserts are each 1/4inch thick while the insert plates are 1/16inch thick, this means that the cork will stick through the plate by 3/32inch (the corks are 1/4inch, that’s 4/16inch thick so cork minus plate is 3/16inch, meaning 3/32inch protruding on each side).

What was needed was to arrange a support for the plate such that it was held 3/32inch clear of a flat surface so I could press the cork inserts in against the surface and that would do the trick, but I needed a fairly accurate 3/32 measure for the job.

Simple and cheap to use for this is silver steel rod, it’s easy to get and its diameter is accurate to a quarter thou’ so it was pop down to Cromwell Tools and get some from their stocks for the princely sum of £0.81 for a pair(plus tax!).

Silver steel

The two lengths of silver-steel

On the other hand there are the new inserts, these of course are now bone dry having been “in stock” for years and they’re a bit fragile so they needed to be softened up a bit.

The way to do this is to soak them, and to soak them in boiling water at that, so I popped them in a pan, added water and brought it to the boil. They were then left to stand overnight and next morning they had darkened in colour and were much softer to the touch and more flexible.

Next was to make up the jig.

This doesn’t need to be anything complicated since all it needs to do is support the insert plate 3/32 above a flat surface while the insert is pressed in.

What it’s doing is to support the insert plate on a length of the silver steel rod above the work-top and then arrange another two short lengths of the silver steel, one supporting either side of the aperture I’m working on.

fitting jig

The jig, lengths of silver-steel superglued onto a backboard.

A piece of composite board formed the base and the silver steel was glued onto it with “superglue”.

Worn plate

Worn plate edge on

This picture shows one of the worn insert plates and you can see how thin it has worn.

inserts

New and worn cork inserts

This shows a pair of the cork inserts, a new one at the top and one taken from the plate below it, As you can see it’s worn to less than half the original thickness and shows signs of charring.

Next step was strip out the old inserts and then fit the new cork inserts into the plate to the requisite depth.

Rather than fit an insert at a time in the jig I found it best to fit every other insert and then use the jig to set them to the same depth.

I then turned the clutch plate over and inserted the others from the opposite side and then levelled those ones with the jig.

recorking plate

The plate 3 parts finished

The first plate on the jig, about 3 parts done.

To make sure the insert corks have a level surface either side of the plate was then touched up onto a sheet of emery-paper taped onto the flat surface until all the inserts were faced in.

 
Linishing plate

The recorked plate being finished off on emery paper

That was one plate done and there are three in all, with 30 inserts to fit into on each plate so it’s not a five-minute job!.

Once all three were done then it was just a case of rebuild the clutch and set everything up from scratch, as was done at  the initial build.

Breathing alterations

I’ve now got about 70 miles up on the old lady.

As said earlier she had a Amal Type 276 carburetter fitted rather than the correct Amal Type 89.

Major difference is that the 276 has a smaller bore so the old girl has been undercarburetted.

This model of the carburetter was fitted to the 500cc Panther of this period and I found it was set up as specified for that bike, not only that but it had the same type suffix on the carb body so I suspect that at some time the carb from the other model has been fitted in error.

Having a few miles up now, and on checking the plug finding her running rich even though there is a No.5 slide fitted and the carb set lean, I decided to bite the bullet and get the correct carburetter for her.

Options were to look for a used one or get a modern rebuild.

On checking with Amal themselves I found that the Type 89 was not available but the slightly later Type 289 was.

The difference between them is that the 289 takes its pilot air supply from the main air inlet while the 89 takes it from holes in the side of the body and I decided to opt for the 289.

After a bit of discussion with Amal I ordered a new body less the float chamber, I do after all have a NOS chamber on her now so don’t see the point of getting another one.

The new body cost just over £170 plus post and the inevitable 20% tax .

Two days later a package arrived in the morning post.

In it was a box full of paper shred packing and an “AMAL” box.

Box

Amal Box

Inside that, wrapped in more packing, was a split new Type 289, already jetted and set up for a 1937 Panther M100 with a full “set up and tuning” leaflet plus an envelope containing the throttle slide spring and a new gasket for between the carburetter and its manifold.

Amal 289

The New Carb

So, out to the garage and fit the new carb.

I had two worries here, the free length available on the throttle and choke inner cables.

First tried was the throttle, and it turned out that there was sufficient free length for the slide to “bottom out”, even when turning the handlebar from lock to lock so no problem there.

But when the choke cable was checked the slide was not bottoming, there was insufficient free length so the cable needed to be altered to suit.

The simple way round this is to shorten the casing of the cable, this has the effect of increasing the free length of the inner cable which is what we want and all that’s needed is an extra 1/4 inch of that free length.

This is one of those fiddly jobs that isn’t often done but if you do know how to do it, it can save you a lot of trouble.

The obvious way is to unsolder one nipple, cut the casing back and then resolder the nipple but this is easier said than done because often solder will not “bite” onto a used cable.

It is however possible to just trim back the outer casing itself without removing the nipple.

To do this you first slide the ferrule back of the end off the casing, up to the nipple and out of the way, this is probably the most difficult part of the process depending on how the ferrule is fixed in place, but using a sharp knife to knick round the casing at the ferrule’s base will normally do the trick.

You can then “winkle” the bit of loose casing cover out of the ferrule and the outer cover needs to be cut back to expose the metal coils anyway.

Then, using your knife press the edge of the blade between the end coils of the casing and then twist the blade to lever them a little way apart.

Step1

Opening End Coil of Casing

You can then turn the blade so as to take the free end of the coil over the inner wire and the casing can then be unwound away from the inner wire for a few turns.

Step 2

Unwinding Casing

Once you have sufficient unwound then just nip off the unwound coils with a pair of cutters.

Step 3

Nipping Off Excess Coils

There will be a sharp “rag end” of the casing left projecting, this can be dressed off with a file or careful use  of a “Dremel” tool and all that is left to do is slide the ferrule back into place and refit the cable.

I’ve found this trick can be useful at the roadside once when I altered a clutch cable from one make of bike to fit another when its cable broke, meant the bike could complete the event and did not need to be “trailered home”.

In Drag

When I first took the old lady out for a ride I found that her clutch was dragging badly.

When you are setting the clutch up, the individual clutch spring tensions are adjusted until you get an even “lift” when the handlebar lever is operated and when I initially set this one up I had problems getting the spring plate to lift evenly.

As the springs are all identical then the amount their adjuster are screwed in by should be fairly close to each other and these were not.

This indicates that the springs are “tired” and should be replaced so I got a set sent up from the Owners Club spares scheme.

To fit them requires a bit of dismantling, on late models there is a separate dome cover over the clutch and to work on the clutch you just need to remove that but life is not so easy on the pre-war machines.

With these you need to remove the complete outer primary chaincase, to remove that you need to remove the footrest and to remove that the exhaust syatem on that side has to come off!.

Primary Drive

Primary Drive

Once the primary case is removed you have access to the clutch and the springs.

There are five springs in the Panther clutch, each fitting into a spring cup in the clutch face-plate and secured in place by a sleeve nut with a screwdriver slot in it.

Clutch Exposed

Clutch Exposed

I unscrewed one of these sleeve nuts, removed the spring and compared it against one of the new springs and found the old spring was noticeably shorter, it must have “settled” a bit over the years.

Springs compared

New and Old Springs Compared

Then it was merely a case of putting the new spring in the spring cup and fitting the sleeve nut, sounds easy but it’s not due to the spring pressure.

Since the adjusters are a sleeve nut rather than a screw you need a special screwdriver with a gap in the blade to allow for the stud that the sleeve nut screws onto.

spring tool

Spring Adjuster Tool

This shows the tool I used, it’s made from a bit of 1/2inch hexagon bar with a 1/4inch hole drilled down the middle and the end ground into a screwdriver blade.

By fitting it into a socket on a “T”-bar I can put an even pressure on the springs and turn the sleeve nut to engage it with the threads on the stud.

The springs were replaced one at a time and then all were tightened down till they were solidly coil bound.

They were then each turned back by four complete turns to give the base setting.

The clutch was then operated several times to settle the springs in their positions and then operated while watching the face-plate lifting.

The springs were then individually adjusted until the plate was lifting straight and even.

As on this occasion there was no need to replace any of the clutch plates there was no need to reset the free play in the clutch cable but if I had renewed the friction plates this adjustment would have been needed.

The effect of new, thicker, plates is to increase the free play in the system and there are two ways to adjust this out.

The obvious way is using the cable adjuster where the cable enters the gearbox but this is limited and there is also another adjustment on the internal lever inside the gearbox.

This adjuster is to be found under the small cover seen here by the kick-start lever.

 Adjuster Cap

Fulcrum Adjuster Cap

This cover is held in place by two screws, once these are removed the cover can be lifted off revealing an adjuster nut which alters the fulcrum point of the internal lever.

Adjuster Nut

Fulcrum Adjuster Nut

Since the underside of the cover is recessed to fit the adjuster nut, the simplest way to adjust this nut is using the cover to turn it.

However the cover must be screwed firmly in place before you can operate the clutch as it is the anchor point for the fulcrum.

Pedalling about

The last of the foot controls needing “adjustment” was the brake pedal and this was also the most awkward one to do.

When I got the bike it was in this shape and not knowing any better, I assumed this to be correct:-

Brake pedal old

Brake pedal “As Was”

Bent Lever

Bent Lever

 

As you can see the way the cables attach to it means there is a lot of “lost” motion of the pedal before there is effective movement of the cables.

Yes “Cables”, this old lady came with her front and rear brakes coupled together as standard.

At the pedal the top cable works the front brake, the bottom one the rear, all this back in the 1930’s, about 50 years before the Japanese manufacturers “invented” the system :^).

On closer examination it was found that the pedal lever was twisted at the point where it curved down and the toe-piece was bent in towards the bike.

In order to bend a steel forging like this it is necessary to get it up to high temperature, when it can be bent like warm toffee, so a gas torch was brought to bear on the job.

First thing to do was take out the twist and removing this almost completely eliminated the bend.

This had two other, connected,  effects though, first was that it very effectively removed the paint from the lever and the other that once the paint was removed an earlier repair was revealed.

At some time before I  got her the old girl has been dropped and this must have been the cause of the bent lever, however when being dropped the toe-piece of the pedal had also been snapped off.

This had been repaired by simply butting the two broken ends together and then brazing the joint up, so effectively the leverage to trhe rear brake was being taken by some brass brazing rod, Not an Ideal Situation!!

If the joint had been splinted as well then it would have been an adequate repair but not as it was.

To make a better repair the break was cleaned up, dressed and grooved.

The whole pedal was then set up on blocks so the toe-piece was correctly aligned and the parts “TIG-welded” together, this way the repair will be as strong as the original pedal was.

Once the lever had cooled down it was then dressed back and then given a coat of etching primer before having the imperfections made good with filler.

A few coats of primer/filler were then sprayed on and allowed to dry overnight.

Once this had been rubbed down smooth and level the black topcoats were added, followed by a couple of coats of clear lacquer and this was the result:-

Repaired Pedal

Repaired Pedal

Repaired Pedal2

Repaired Pedal

Now the cable is making a 90 degree angle with the lever arm when at full stroke, which is what is required, not only that but the “lost motion” has been eliminated, giving a better “feel” to use of the rear brake.

Kickstart Repair

The repair to the kickstart was a bit more involved. On this there is a foot-piece which pivots on a boss formed on the main shaft of the pedal.

The problem was caused by the “eye” of the footpiece being worn. This had allowed it to slide against the limit stops so these were worn as well but fortunately there was very little wear on the boss the footpiece pivoted on so it was decided not to worry about the boss.

The “eye” first had to be bored out until it was a true bore, simplest way here would have been to clamp it on the table of a vertical mill and clean it out with a milling cutter.

Not having a mill I clamped it in a 4-jaw chuck on the lathe. To get it centred I cheated a bit by clamping a bit of 1/2inch bar stock in the tailstock, putting it through the “eye” and clamping the footpiece in the chuck using that as a guide, being a trusting soul though it was checked before commencing work.

In Lathe

Centring the pedal in the 4-jaw, The mandrel is purely to aid in this.

Once the footpiece was clamped up it was soon bored out true and enough oversize to take a thinwall bush.

To fit the bush it was frozen with an aerosol blaster and dropped into the “eye”.

As intended it proved too tight to fit onto the boss and so was reamed to a slightly stiff fit and then the boss burnished to ease the fit.

Next job was to make good the limit stops which had worn angled.

Footpiece

Foot-piece opened out and bushed.
The limit stop has been welded up but not yet reshaped

These were filed back to square. This meant however that in the “at use” position the footpiece was angled backwards so the stop on the pedal was built up with weld and then shaped using a Dremel grinder so that it stopped just before the right angle position and the stops were making full contact.

Doing this means that as pressure is put on the footpiece your foot will tend to slide in towards the pedal shaft rather than out and off the end of the pedal, something that is not to be recommended when using any kickstart, never mind one on a 600cc, long-stroke, single.

The foot-piece was assembled onto it’s shaft but when the end nut was fitted in place there was more vertical play than I liked, the nut was bottoming out on the end of the boss before it reached the top of the footpiece.

This was got round by making up a recessed washer to go between the nut and the end of the boss that would take up this play and once this was fitted the kickstart was as good as new.

Gear Reset

After re-routing the clutch cable, next of the problems to be fixed was the gear-pedal.

This is an alloy lever and a characteristic of this material is that it will age harden, that is as it ages it becomes harder and less flexible so if you try to bend it “as is” it will almost certainly break.

If it is heat treated, or “annealed” first then it can be bent, but you need to be careful since it also “work hardens”, this means that the bend should be put in in one smooth pull.

The lever had to be heated to the correct temperature, the easy way to determine this was to smear some soap onto the lever and then gently heat it until the soap blackened.

The spline end of the lever was then clamped in a vice and steady pressure put on the other end to move it across by the required amount.

lever reset

Re-setting the Gear Lever Alignment

This meant that the toe-piece was now at the wrong angle but as the whole lever had been annealed then this could also pressed  back until its angle was correct.

Toe reset

Re-setting the Toe Piece

When the pedal was put back onto the bike it now cleared the exhaust sufficiently that the pedal could be moved far enough round on its splines for me to be able to change gear easily.