TIMING TOOLS

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I recently bought myself a new toy, an LE Velo which was part restored but complete.
It’s a a bit of a mongrel as it has a MKII chassis fitted with a MkIII power train and this has led to some problems.
As I got it it was a runner, easy starting but totally gutless, I had had an LE some 50 years ago so I knew the performance to expect and this was nowhere near, it was down to about Cyclemaster levels!.
As there was a lot of free play at the twistgrip I went to check that I had full opening at the carb and encountered the first “Gotcha”, the coolant hoses came away from the stubs at a touch, yes the stubs were rotten!
This brought about another problem, I now needed the correct Imperial sized spanners so it became trips round the autojumbles to get the spanners needed, although I did also find a couple of (expensive!!) sources on the internet, then it was dismantle and remove the cylinders and get new stubs fitted.
I joined the LE Velo club, sent down for gaskets manuals etc and the rebuild started.
There were no difficulties until I learned constructive use of foul language when I came to setting the tappet clearances, accessibility with the engine in the frame is, er, a little limited shall we say!
Anyway with the engine back together I finally got round to the carburetter and found I was not even getting half throttle at max, and all adjustment had been already been taken up.
On looking in the spares lists I found three different cables listed, which was the correct one?, and remember my bike is a hybrid!
So I took the easy way out and made up my own cable, including a mid-way adjuster, which was just as well!.
This was when I discovered the delights of the MKII LE throttle assembly!. I must admit it suits the bike better than a modern quick-action type would but it is a surprise when you first encounter it, an involute scroll is not a common system!.
OK, time to fire her up and see what’s what. Fuel on, choke on, a quick tickle, kick her over a couple of times to prime the engine, switch on and kick and the little lady’s running, talk about an east starter!
Rev her a couple of times, and find she would not rev free and was not running well.
It was apparent that the timing was out. So check the book on how to do it.
Book says – “Set to TDC by centring the mark on the flywheel in cut out”, fair enough but something did not seem right and a quick screwdriver down a plug hole showed the piston was not at TDC.
Checking the books and I found that the flywheel is not keyed in position and that, electrically speaking, the flywheel alignment did not matter, the marking was only to allow for easy timing and that as long as the points opened at TDC, having the marks out only meant that the emergency start facility would not work. From previous experience of these “emergency start” systems this did not worry me!
How to find TDC?, it’s easy. You just drain the cooling system and remove a cylinder head! sacrificing some coolant and a new head gasket in so doing!
There must be another way, thinking cap on!
The best way to find TDC is by using a piston stop, how to do this on an LE though??.
On a OHV machine you can poke something down the plug hole, straight down onto the piston but the LE is a side-valver, the plug is to one side and at a shallow angle. I had a spare head so I got this out and had a look and then went out into the workshop.
I had a length of 15mm brass hexagon bar in stock so this was chucked up in the lathe and one end skimmed down to 10mm OD for 43mm.
This was again skimmed down to 9mm diameter for 33mm so I now had a stepped rod with a hexagon head.
The top, 10mm diameter, length was then threaded 10mm x 1.0mm (10mm spark plug
thread) and all this gave me the desired piston stop.

    Piston stop

I tried this out in the spare head and it showed the end of the bar protruding to about 10mm below the lower surface of the head above the piston, IDEAL, just what I was looking for.


Piston stop in head

Showing stop protruding below head.

Next I needed a mount for a degree disk.
I could not mount a disk direct onto the end of the crankshaft as it would foul on the ignition coils so it was back to the stock box where I found a length of 30mm diameter aluminium bar and that went into the lathe.
I turned down the end to give a 1mm high stub of 15mm diameter, intended to fit neatly into the centre of an old CD disk.
I next drilled a 4mm hole about 35mm deep down the middle and parted off first a 25mm length and then a 5 mm length.
I tapped the hole in the longer piece to 2BA and opened that in the shorter to 5.5mm, this gave me the stand off mount I needed.
My intention was to stick a degree disk onto an old CD so my next step was to download a picture of a degree disk from the Internet.
I printed it out on card to 125mm diameter. I then found this was too big for the CD and decided not to bother using the CD after all. So I cut the disk out, made a 5mm hole in the centre and I was all set.

  

 Disk stand off parts

Bike up onto the bench and raise rear wheel clear of the deck, front cover off, remove centre bolt from the advance unit and replace it with a short length of 2BA studding. Next was to thread the longer of the ally stand offs onto the studding and wind it down till it was in contact with the advance unit.

  Disk standoff

I put the degree disk onto this and then slid on the thinner ally disk followed by a 2BA washer and nut to secure it in place so I now had my degree disk mounted onto the end of the crankshaft.
I rigged a pointer onto the disk from the lower of the retaining studs for the front cover
and removed both spark plugs.

  Degree disk in place

I made sure pistons were well down the bores, replaced one of the plugs with the stop, put the bike into bottom gear and slowly turned the engine over with the back wheel until I felt the piston touch the stop.


Piston stop in use

A look at the degree disk and I set it to show 40 degrees before TDC (Figure pulled out of the air as a guestimate!) and a note made of the figure.
I then turned the engine slowly backwards until it again touched the stop.
A look at the degree disk showed it reading 26 degrees after TDC so the total distance between the two stop points was 66 degrees.
I adjusted the disk to show 33 degrees, the half way value, and then turned the engine forwards again till it once more touched the stop.
A check of the disk showed 33 degrees again, showing the disk was centred so I removed the piston stop from the cylinder-head. slowly turned the engine forward until I had reached the zero mark on the disk and the engine was at TDC.
I removed the degree disk assembly and sure enough, a look in the cut out showed a clean flywheel, no sign of the marker dot so a quick dab with a magic marker gave me a reference mark for future use. A check of the points showed them firmly closed.
Next was just to extract the advance unit and reset the timing as per book.
A bit involved but it gave me an excuse to play on the lathe and saved the time needed to get a new head gasket up from the LE club.
It was a useful waste of a couple of days and another advantage is I that now have the ability to set the timing at full advance (of 29½ degrees) rather than full retard, a more accurate method but is it necessary for a low performance side-valver?. Surprise here is that Veloce quoted the advance on the LE to the nearest half degree but on the much higher performance singles it’s only given to the nearest degree!.

BMW INDICATORS FAULT (Flash Can Replacement)

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I’ve had an intermittent fault with the indicators on the BMW sidecar outfit for a while.

Problem with an intermittent is that when you go to fix it, it doesn’t appear or you do something, it disappears and you think you’ve fixed it but next time out it appears again!.

Anyway, this time instead of being slow and dim the both sides indicators stopped working altogether, pointing to a fault in the circuit before the switch, i.e. the flash-can, wiring to the switch or possibly the switch itself.

So after a look at the wiring diagram I saw that if I jumpered two of the can terminals I’d be putting power direct onto the switch, bypassing the can. This meant unplugging the can from its socket and connecting across the two terminals in the socket, 49 and 49a.

Once I’d done this I tried the switch and both sides of the indicators would light, showing that the switch was working ok.

Next suspect was the can and on a closer look I could see some heat distortion of the plastic case and there was a smell of burnt insulation, I popped the case open and it was stinking burnt, well it is about 45 years old so I don’t think I can complain too much.

So on line for a replacement can and find that they are priced at just over £52 each, seems it is an odd-ball unit that’s now obsolete.

Being of Scots blood and hence objecting to such a price I had a look around for an alternative,

I found that the official can had four terminals, power in, earth out, power out to switch and power out to warning light and while these come out as standard 6.3mm spades it does not fit the industry standard relay socket.

A little study turned up an equivalent unit at a price of £7.60 but it would not fit the BMW’s socket, it of course being designed to fit a standard relay socket.

This simply meant that I bought a matching socket to go with the new flash-can.

Before committing myself to wiring alterations I connected the new can with some short leads onto the old socket.

On the flash-cans each terminal is identified and anyway there is a DIN standard for labelling relay connections, terminal 31 is earth, 49 is power in, 49a is power out (in this case to the handlebar switch) and C is to the warning light and as these numbers are marked on the relay it was easy to cross connect.

So next was Ignition on and try the indicators and they are working beautifully so it was just a case now of changing the sockets.

There was a choice of two ways to do this. The new socket came with a set of contacts to be crimped onto wires and then inserted into the socket but I opted to just remove the contacts from the old socket and simply swap them into the new one.

The contacts are held in place in the socket by a locking tab and it is possible to retract this tab by careful use of a jeweller’s screwdriver, a look at the new socket and then at one of the new contacts and how it fits into the socket makes it clear how to do this.

Once a contact was removed from the old socket it was simply pushed into the corresponding place in the new one and then all that was left to do was put the new can into the socket, put it in place inside the headlamp shell and that was that!.

CABLE “BIRDCAGE” TOOL

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If you refer back to the blog post of 14th August 2013 entitled “Under the Wire” you’ll find a piece on making up control cables.

In this I used a crude method of splaying out the end of the inner wire, basic but it does work.

I was recently shown a special tool for doing this which made a better job of doing this. When I went “on line” to find this tool I discovered that it had a ridiculously high price for what it was, just over £123.

Having had a good look at the tool I knew that I could make one for myself, so I got a length of 8mm by 25mm “bright steel” bar.

I cut two 100mm lengths from this, I put them one on top of the other in the drill vice on my post drill, squared them up and put two 5mm holes through them, on the centre line, one each about 20mm from either end. I then opened out the holes on one piece to 6mm clearance and tapped those in other bar to a 6mm thread.

I could then bolt the two bars tight together, hold them in the bench-vice and draw-file one long face to ensure that both bars were dead level.

I took the bars apart and then re-assembled them with a piece of card, about 0.16thou thick, between them, put them back into the drill press vice. I next put a pop-mark, spot-on the centre divide and in the middle of length of the bars, and then another two, one each about 25mm either side of that.

Next step was to drill a 6.1mm hole, 10mm, deep at each pop-mark.

As there are three different cable sizes to accommodate I then extended these through the bar, one with a 1.5mm drill, one with a 2mm drill and one with a 2.5mm drill.

Now comes the crafty bit, A standard drill has a 118° point so each of these holes now had a shallow conical join where the drill size changed. I wanted a deeper cone here.

You can get what is known as a “spotting drill”. This is intended for marking out work, not for hole drilling, and it has a 90° point so I took a 6mm spotting drill and deepened each hole by about 2mm.

That was the main body of the tool made, I dismantled it and discarded what was left of the card.

I now had to make three punches, one for each size of cable.

I cut three lengths of 6mm round steel bar, each about 5 inches long, fired up the lathe and squared off the ends.

I then used the spotting drill and sunk a 90° socket in the end of each, these were to form the cable end into a double conical “birdcage”.

As the diameter of the relevant cage for each cable diameter was different I now needed to form the punch ends appropriately, a diameter of double that of the cable itself was about right. This meant that to achieve this I would need the open end of the conical punch to be that size and I achieved this by cutting a 90° taper onto the end of each punch until its socket was of the required diameter.

To form a cable end I now have the tool body assembled loose, put the cable end into the appropriate bore and nip up the bolts. Because the bore had been made with the card between the bars the bore is undersize and the cable is firmly held in place.

The appropriate punch is now inserted into the larger top drilling and pushed home. The cable can now be slid further up in its bore until it bottoms in the punch socket and it then further in by its own diameter.

The tool is then bolted tight shut and placed in a bench-vice to hold it and the end of the punch struck with a hammer. This forms the end of the cable into the required “birdcage” which will lock it in place when the nipple is soldered in place.

I could have made this up using angle iron to be easier to hold it in the vice but the only “bright steel” angle I could get was either way too big or if in a convenient size only had a 3mm thickness so I had to use the plain “bright” bar.

CRUNCH TIME ON THE COMBO

I’ve had a problem with the gears on the BMW combo for a while now, what’s happening is that it keeps jumping out of second gear under load and then dropping back in with a crunch.

I’ve been working round it by doing a double change up into third from first and not using second but that’s not fixing it and it’s a wide gap between first and third.

I recently had the chance to get another gearbox and jumped at it so now it’s time to change the gearboxes over.

As the sidecar limits access on one side, what is an easy job on a solo becomes a bit of a fiddle and the fact that it’s a /7 power train in a /2 frame does not help since it’s a tight fit!.

First thing is to run the rule over the replacement gearbox, all seems ok, changes gear without problems but the neutral switch is damaged, one of the electrical connections has been broken off, well I’ll just swap over the one from the current gearbox while I’m doing the swap.

So it’s out to the bike and get started, I need to clear the decks round the gearbox so we start by removing fuel tank and then the silencers.

Then it’s a case of take off both carburettors and their associated plumbing, I’ve left them attached to their cables and tucked them away at the front of the engine unit.

Now I need to remove both halves of the air-box. Left side comes away without problem, well it needs to, to be able to allow for the filter being changed but the right side hangs up, it’s not till I’ve removed the securing nut completely that I find a washer jammed in the slot that’s meant to allow the cover to slide off to the right side of the bike by just slackening the securing nut.

As the engine breather hoses go into the side castings of the airbox the easy way to get these covers off is to remove the top cover over the starter motor, because the ignition coils are positioned on the frame just above this cover it’s “a bit of a fiddle” to get it off and then we have the decks around the gearbox cleared for action.

But we’re not ready to remove the gearbox yet!, it’s still connected to the bike itself.

A BMW has a shaft drive and the shaft itself has a universal joint that bolts onto the output flange of the gearbox. This joint is under a rubber bellows and runs in oil so that needs draining and the bellows pushed back to allow access to the four 12-point head bolts securing it. Space is limited by the bellows so this is another right fiddle, and replacing them can be worse!.

As clearance with the rear sub-frame is tight it makes sense to remove the clutch operating arm, remembering to catch the return spring as it drops clear.

Now we can go round and slack off the four mounting bolts for the gearbox proper, as I have the combo’s battery mounted on the sidecar I have the main ground return from the battery secured to the lower right of these (remember this combo is a right-hooker!).

While it should now possible to remove the gearbox, clearances are VERY tight and to give more space the trick is to remove the rear swing fork pivot pins and move the complete rear wheel assembly back, it only needs to come back about an inch to make all the difference but of course up till now the bike has been standing on its wheels.

This means getting the jack out and lifting the rear end of the bike enough to drop the centre stand, because the bike has a 15inch rear wheel rather than the original 18inch, as well as a 16inch front wheel, to just try to simply lift her onto the centre stand as normal risks a rupture! But once you have her lifted up, dropping the stand becomes a safety measure, think of axle stands on a car.

Now to loose off the rear swing arm! First thing is to undo the rear brake linkage as this will prevent the wheel from being pulled back, undo the bottom ends of the rear suspension units, take out the bearing support pins and pull the wheel back.

Now comes the gear-change parts, this bike has the Kinematic assembly and the simple wire link has been updated with a rose-joint assembly.

There’s a lock-pin you need to remove from the front rose-joint that then allows the joint to split, once that’s done simplest way is to just drop off the entire left side footrest assembly.

Now the gearbox can have the mounting bolts removed, the top right one is a nut onto a stud into the main engine block and it is easiest to remove this completely, the gearbox can then be lifted clear, remembering to disconnect the neutral switch as you bring it away.

As mentioned before, I need to swap the neutral switches between the two gearboxes. I also need to fit the clutch pushrod into the replacement gearbox as this cannot be done with the gearbox in situ.

Next thing is to simply have a cuppa have a good think round and make sure nothing has been forgotten about before fitting the new gearbox in place.

While things are opened up it’s a good idea to clean and re-grease the spline drive on the clutch. This needs a black moly HP grease, but don’t overdo it! You don’t want any of that on your clutch friction plates!!

Now you offer up the box onto the bike, remember to fit the wires onto the neutral switch, it’s a real bitch of a job fitting them when the box has been installed, with the clutch push-rod pressed back into the gearbox align the input shaft with the centre bore of the clutch and slide the gearbox into place.

Once you have it home on the engine casing you can refit the mounting bolts and the stud. When you have that done it’s just a case of refit the rear swing fork into the frame and you can have the bike back on its wheels. Remember that you disconnected the rear brake!!

Then it’s just a case of reversing the disassembly work, fill the gearbox with oil, put about half of the spare gearbox oil into the swing arm and the jobs done.

Quick trial and find the neutral light not working, as this inhibits the starter it means the engine won’t start so it’s down and check the switch connections, I’d had a meter on the switch to ensure it worked before we started.

One of the switch terminals should go to a ground at one of the gearbox mounting bolts and this wire had broken at the tag of the terminal held under that bolt.

Sounds an easy fix, BUT, – the wire is now the exact length to reach the mount bolt tag, there is no extra length to allow it to have the end stripped back and fitted into a new tag and then to fit this under the bolt head!

Only access to this wire now is from underneath the bike so its a case of preparing an extender piece of wire and then to grovel alongside the bike, reaching under it, preparing the wire from the switch and then crimping on the extender, sounds easy but you try doing it!. Anyway, I managed it and made off the new connection under the bolt head.

Key back in, ignition ON and I’ve a working neutral light, try the starter and the engine turns over so next it’s a case of fuel on, hit the starter and she’s running again, time for a road test.

BLOODY TYPICAL!!

Well I’ve just been out in the garage to fit the new barrel onto the Panther only to find I’ve made a major cock up.

I had the barrel in place over the crankcases, slid the gudgeon pin into place, circlip fitted in place and slid the barrel down to seat on the cases and – – – IT DIDN’T BLOODY FIT!!.

The barrel spigot was too large for the cases!

So out with the circlip and gudgeon pin, barrel off the bike again and start the inquest.

Vernier out and check the spigot outer diameter against that of the other barrel and it was definitely larger, What’s going on?.

Sudden thought “It can’t be!” but measure barrel lengths. The old barrel is 3mm shorter than the new!.

Yes, the barrel I had had bored, the one that had a slipper piston in it and was tagged as being for an M100 is in fact for an M120! Just what I need!.

When I first built up the bike I’d got a job lot of spares as well, all said to be for the M100

There were 3 barrels, the one I’ve been running on, the one I now know to be from an M120 which has the new bore and piston and one other M100 barrel (Yes, I’ve measured it to be certain!). I know, I should have checked but the possibility never crossed my mind, especially as it had come with a slipper piston in it and the M120 did not use slipper pistons.

So a closer look at the two M100 barrels. There’s the one I’ve been running on and the “spare”. The spare turns out to have been bored out to plus 60thou while the other is on STD bore.

What is the wear like on them?. I used the old dodge of checking the ring gap in the unworn base of the bore and at half stroke and the “spare” comes out best with an increase of only 4thou.

The other barrel is about twice this, still plenty of life there but I decide I’ll put new rings in the “spare” and use that since I’m unwilling to bore either out for the Rover piston. Why had I not used this barrel originally? Quite simply because I had a set of new piston rings “in stock” to fit the barrel I did use.

So it’s now a case of clean up the outside of this barrel with the wire brushes and give it a coat of paint.

I got onto POC Spares for a set of new rings. I placed the order at about 10.00pm on the Wednesday night, parts arrived on Friday morning!! Well done to Old Foxy!!

Of course new rings meant that I had to set the ring gaps. I used the old advice of “4 thou for every inch of bore” and had to open up all three from a tight 10thou.

I cleaned out the ring grooves in the piston using the old rings to scrape out the crud, the middle ring had been a bit tight in its groove but all 3 are now an easy fit in their groove.

Because it was an old piston and I was not happy with the condition of one of the gudgeon circlip grooves I decided to fall back onto older technology and use gudgeon buttons rather than circlips, there’s a choice of materials here. My old Triumph uses these as standard and they’re phosphor-bronze, I know some of the racing boys are using Teflon or there’s also the option of aluminium.

If I choose phossy-bronze, well it’s not an easy material to work with since it work hardens on sight, I’ve looked into Teflon but this means buying an industrial length bar of the stuff and it’s not a cheap material so it looks like I’m going for the aluminium option, I’ve a foot length “off cut” of inch bar in stock so it’ll give me an excuse to play on the lathe.

So first thing is to work out just what’s needed, sit down with the piston, the gudgeon pin, a vernier, a sheet of paper and a pen to work out dimensions and sketch out what’s needed, then it’s out to the lathe.

First was measure the length of the gudgeon pin, subtract that from the bore dimension and half the result. This gave me the length I needed for the gudgeon buttons, next was the diameter of the pin and then its bore, what was needed was a “top hat” to match these dimensions.

Pop the ally bar in the lathe and skim about an inch and a half length of the bar down to 7/8 inch diameter and check against the piston, I used the old piston from the M120 barrel as a gauge for this.

The bar was a tight fit in the piston so I skimmed another couple of thou off it and tried again, an easy slip fit!.

Next step was to skim the last 10mm of the bar down to be a snug fit in the bore of the gudgeon pin itself, as the pin is taper bored this proved a bit fiddly but it was managed.

Next was bore a 3mm hole down the middle of the bar, part off the first button to length and then repeat the whole process.

Snag here is that these buttons are flat faced, but they have to go against a round bore. A look on Google gave me the required clearance to skim a shallow taper onto the face so that only the central few mm of the button was able to touch the bore and as they have to run with a slight clearance to the bore, same as the piston skirt, it was a simple job to skim that in.

Now the acid test, put the buttons into the pin and try it in the bore, an easy fit with a nice clearance to each side, jobs a good ‘un!, now to build things up again.

A not uncommon trick with a rebuild is to put the piston into the bore first and then lower it onto the head studs, sliding the gudgeon pin into place and fitting the circlips before sliding the barrel into place.

What isn’t said is that it can be a right fiddle getting the small end eye to line up with the gudgeon pin bores at all as the con-rod keeps trying to fall forward, and then you have to get the match exact enough that the pin will slide home through both the piston and the small end, remember that there is no clearance between these, it needs an exact match. At least there was no trouble with fitting the pin circlips since I was using the buttons.

After that it was just put everything back in place, believe it or not the biggest fiddle was replacing the exhausts!.

What is needed here is for the flange on the pipe to fit flush against the stub on the head. If you try to put the complete pipe and silencer in place as a unit, the flange will be on a tilt against the stub and you will not be able to pull them flush to using the retaining nut to get a seal, you need to have just the pipe in place and pull up the nut while wangling the pipe around to make sure everything mates up square before rotating it into place and fitting the silencer last, – – – and then you have to repeat on the other side!.

All that’s left to do is fit the carb, then the tank, add some fuel and give her a kick.

Story book ending is to fire up first kick and settle to a steady tick over.

Well second kick the old bitch kicked back and it took another couple of kicks before she was running and the carb needed setting up.

On initial kick over compression was down but after taking a couple of miles run it came up to reasonable and it’ll take a couple of hundred miles to bed the new ring in so all in all I’m happy with the result, just have to see how much oil she’ll be using.

What to do with the rebored M120 barrel? Well I’m considering skimming the spigot down to suit and shortening the barrel, this would have to be done on a mandrel but it is possible, or I could always source another M100 barrel and bore that to suit the Rover piston, it’ll depend on oil consumption once the rings have bedded in.

Getting Bored

The old Panther has been getting a bit greedy lately, in fact it’s been getting so that I needed to top up her oil just about every time I filled her petrol tank.

Now Panthers are known for their thirst for oil but this is a bit extreme, even for one of them and so it was obvious “something needed to be done!”.

One reason given for their thirst is their old fashioned oil ring technology, straight out of the early 1930’s!. Bearing this in mind, as well as the fact that the old girl had been rebuilt onto a worn bore and that I’d put another 4kmiles at least onto that, I decided to try a new bore.

There is a conversion available through the Panther club where you replace the piston with one from a Rover 3.8 car engine, This involves some modification work to be done on the piston but an already modified piston is available through the club, as are all the required gaskets for the job.

It means over-boring the barrel to plus 75thou but there is sufficient “meat” in the barrel to accept this and still be able to take the next oversize! These old girls were well built though, and to last!!.

When I originally rebuilt the old lady there was a choice of barrels to use. The one I selected had the better bore but a broken fin and I used this in preference to the cosmetically better but worse worn barrel so this is the one that has been bored out to suit a club piston.

I had asked for the barrel to be bead blasted before being bored but this was not done so I had to set to with wire brushes on the barrel once I got it back to clean it up for painting.

It was then given 3 coats of black “Smoothrite” from a rattle-can and put out in the glazed porch to harden off in the sun for a week.

Barrel

The barrel resplendent in its new paint

All this could be done before a spanner needed to be set on the old lady herself and that moment had now almost come!.

A decision had to be made as to the cylinder head. This would need to be repainted to match the barrel. It’s a cast iron head so the obvious seemed to be to just black it the same as the barrel. BUT! An option appeared.

Back at the time she was originally built the “go to” option for the more sporting bikes was to have a bronze cylinder head, aluminium alloy technology not yet being up to that job and, knowing that there had been a number of bronze heads cast for Panthers, I could paint the head in bronze!. Decisions! — Decisions!!.

Anyway before I could do the head I had to remove it from the bike so it was out into the garage and start the dismantling work.

As always stripping off the ancillaries takes longer than the actual dismantling but the old lady soon stood with her head stripped off.

Looking into the barrel I could see the piston crown was oily so that explained the high oil usage!.

I tapped the head through-bolts down to level with the top of the barrel and then left her there while I got to work on the cylinder head itself.

A session in the wash tank got the head cleaned of oil and then it was a case of out with the wire brushes to get it down to as near bare metal as I could before painting began.

Also required before paint was applied was to mask off the exhaust stub threads and the joint faces, it’s surprising just how fiddly a job this is!

I went onto ebay and got a tin of a high temperature bronze paint, paint intended for brake callipers and I’ve given the head a couple of coats so now we’ll just have to see how well this paint stands up to the temperatures round the exhaust stubs!, if it come to the worst I’ll just give the head a coat of cylinder black and go back to standard.

Bronze Head Head & Barrel

The cylinder head in bronze and it fitted in place

It looks a bit bright here but it should dull down with a bit of use, otherwise I can add a spot of black to the paint left in the tin to mute it down a bit and give the head a coat of that.

A snag when re-building a Panther engine is that the standard cylinder bore is 87mm. The biggest of the easily available “Terry’s” piston ring clamps however only goes up to 85mm. It can be stretched to cope with 87mm but it won’t cope with the 89mm Rover piston so the usual assembly trick of sliding the barrel onto the piston with the rings in a clamp won’t work, especially since the overboring takes out most of the usual taper lead-in from the barrel base.

This means I’m going to have to assemble the piston into the barrel and then offer the barrel and piston together up to the crankcases, slide the gudgeon pin into place and fit the circlip, what could easily be done on my own has just become a two person job, one to handle the barrel and the other to fit the gudgeon pin!

Anyway the original barrel is now off and I’ve got the crankcase face all cleaned down, I’ll use some Hylomar as a sealant here on re-assembly to try to keep the joint oil-tight.

A Bit of a Wobbler

When out on the BMW sidecar outfit at the weekend I noticed a trace of steering wobble that was not there before.

Once back home I checked things over.

First check was tyre pressures, especially the front wheel. These checked out in spec.

Next was steering head bearings, and the front wheel bearings while at it, these were all free and had no play so that was something else crossed off the list.

Next in line came the rear swing fork and wheel bearings. Some play was found in here in both horizontal and vertical planes.

This cleared the swing fork bearings, if these had been at fault the play would have only been found in the horizontal plane, so new rear wheel bearings were indicated.

Thing is that the rear wheel in my combo is an EML unit and NOT a BMW one so the bearings in it are different to those shown in the spares book, and, as I wanted to have the new bearings “in hand” before I started work, I needed to know what they were.

An email to EML themselves failed to receive an answer so I tried the BMW lists on the internet. I received an answer from a member in the States who has an EML outfit with the bearing numbers and I soon managed to get a set from a local bearing specialist.

So, to work!. First thing is to get the bike up onto it’s centre stand. Not as easy as it sounds because the reduced tyre sizes I run have lowered the bike. It’s only by about an inch but the roll-on action of the centre stand no longer works, you need to do a dead weight lift of the bike to get it high enough to lower the stand and it’s b—-y heavy, in fact it needs the use of a jack to remove the risk of a rupture!

Next is that as I am running a non-standard tyre, a wider section car tyre, on my rear wheel the normal BMW quick removal system does not work, the tyre will not clear the brake shoes and drive hub, I have to remove the wheel complete with the rear bevel box and this is not as simple a job as it seems.

First is to disconnect the rear brake rod, next drain the oil from the drive shaft housing, undo the 4 nuts securing the bevel box to the swing arm, remove the lower mounting bolt from the right hand suspension unit. (Oh and it gives more clearance to work if you remove the offside silencer to start with)

Now you can remove the rear wheel spindle and pull the entire assembly back out of the frame, and it’s heavy!!.

Once I had the assembly clear I could lift the wheel away and have a look at the bearings. Sure enough they had been fitted with the bearing numbers facing inwards so I could not read them! Typical!!.

As my rear wheel is literally a car wheel bolted onto the bike hub the next step was to remove the wheel from the hub, just a case of undo the three lug nuts. (The wheel I’m using is from a Citroen car, typical French skimping on an engineering job! Just use 3 lug nuts when everyone else is using either 4 or 5!!).

With the hub clear it was now just a case of using a long drift to punch out the old bearings, heart in mouth moment as I checked the bearing numbers then the relief of finding I had the correct bearings in hand!.

Replacement was simple just thoroughly clean the hubs bearing seats and bore, grease up the new bearings and the spacer and hub bore and fit the new bearings in place, the old bearings make a good pressure bush for this and all that’s left to do is re-assemble everything and find that the wheel is locked solid when I nip up the spindle nut but will turn when I ease the spindle nut!

Guess who forgot the spacer between the hub bearings and the drive?.

On the original BMW hub this is captive, held in place by a separate grease seal between the (open) bearing and the drive. EML widened the gap between the bearings by substituting sealed bearings for the bearing/grease seal pair and using a loose spacer on the spindle instead. An improvement giving a stronger hub for sidecar use BUT!.

This resulted in blue air and a frantic search for the missing spacer!.

Once it had been found and installed, the wheel was now turning easily and I could look to refitting the assembly onto the bike.

Simple way was to put a 4 inch piece of timber down and stand the wheel assembly on that. Doing this brought the bevel box up into near its correct alignment with the rear fork and made it a simple matter to bolt it in place and refit the suspension unit and the rear wheel spindle, not forgetting the rear brake actuator rod.

An AHA! moment

Well I’ve been busy on the LE again and think I may have found the ignition problem.

I needed to know what depth I had between the top of the ignition unit’s top plate and the bore in the end of the crankshaft, this meant taking out the fixing bolt and when doing this I steadied the shaft from turning by holding the unit, as soon as I had eased the centre bolt a little I felt the bob-weights move under my fingers when they had been solid before.

On trying the unit I found the bob-weights would now open out readily. I re-tightened the centre bolt and found they were locked up so that while the engine had been running it had been locked on full retard, no wonder performance had seemed lacking!. It looks like the last person working on the engine electrics had over-tightened the retaining bolt and jammed the unit.

Hopefully the unit has not been damaged by this but we’ll have to see.

I’ve since tried her up the back lane and she seems a bit livelier, but I’ve found that I omitted the seal between the carburetter and the inlet manifold when I put things back together last time. On having a look at the seal it appears to have been cut from a piece of old inner tube, it’s certainly been either knife or scissor cut so I’ll need to get a new one up.

I’ve just totted up what bits I now need, it may be small stuff but it totals out at about 21 quid so It’s worth sending down for them.

It’s amazing how it’s a number of small things are giving the problems now! I had thought that all that was wrong with her was the corroded water pipes! But I suppose that’s what happens when you take on a rebuild.

A New Addition

I decided to go the drill blank route to make the ATD extractor so ordered up a 3.5mm drill blank and a 1 inch long 5/16 BSF bolt along with a couple of nuts.

I now needed to determine the requisite lengths for the extractor parts, I did have suggested dimensions from an internet posting but I’ve learned to always check these before use.

To get the dimensions I need to remove the front cover from the engine. Under this cover is an inner cover carrying the two ignition coils and the points. Behind this cover is the generator and flywheel, the ATD mounting onto the nose of the flywheel with a bolt going through the ATD plate into the hollow nose of the flywheel.

I immediately ran into a problem!. The LE is a small machine and is built low to the ground, to access the front end of the motor you need to not only get down on your knees but have to grovel and I am no longer as young as I used to be.

This pushed me into deciding to do something I have thought about for a few years now, but with the other bikes I had managed by getting a wheeled stool, I decided it was time to get bike lift!.

A problem I have with this is space, a lift will have to be kept between two bikes with another on it, I’ll need to wheel it out to work on a bike but then put it away when finished for the day as I have to get the combo in as well, (insurance demands that it is garaged any time it is left unattended!).

So it was a case of get a notebook and pen ready and fire up Google!.

I’d already decided to go the whole hog and get a table type lift rather than a simple frame jack, (these are not really suitable for use on a BMW anyway) so it was a case of see what was available.

Having recovered from the shock of seeing the prices being asked for the powered types (and realising that my little compressor was not man enough to power them!) I decided it would need to be one with a hydraulic jack.

This brought the prices down to the “reasonable to pricey” range.

Next was size, turns out that some are shorter than a bike so it has to sit on the front wheel and a jack under the frame or a centre stand, an under frame jack is not suitable for a BMW so one of these would mean putting the bike on its centre stand then dragging forward to the front of the table again before lashing it down to keep the rear wheel aloft. The idea is to make it easier so beggar that type.

Anyway I settled on one from CJ Autos that would fit into the available space, was a reasonable price and available; It’s in the garage now, fits nicely into the space available, the LE is up on it now and I’ll be able to make a start on producing the extractor tool tomorrow.

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It’s now tomorrow and I’ve been out in the garage most of the afternoon, the morning was largely spent walking the dogs.

First thing was to get the combo out and get some space to work in. I moved the table out into the space to find it has the “shopping trolley” problem in not wanting to roll straight, a nuisance when it weighs over 100kg but liveable with when you know about it.

Next thing was to run the LE up onto it and secure it, the front wheel clamp works but is awkward to wind in when one hand is supporting the bike, I’ll have to look into this when putting one of the bigger bikes up on it!, a bike support mount might be a better idea

Anyway I added a couple of the trailer straps to steady the bike before I tried to lift it, then it was fit the pump pedal and try it out.

Nae bother! Up she went and I popped the locking bar into place.

I had to remove the front cover from the LE engine unit next and straightaway I found a snag.

Clearance between the front mudguard and the front of the engine is limited and I found that while I could remove the bolts securing the cover there was not enough clearance to remove the cover. Normally you’d put the front wheel over to one side and then there’s plenty room but the wheel clamp prevents the wheel twisting.

Fortunately the stand on an LE does not lift the bike off its wheels so I could safely roll her back far enough to get the wheel to turn far enough for clearance but could not have done it with a BMW, one lesson learned!.

With the cover off and the table raised there was no need to grovel to see what I was doing. The first thing was to have a look at the ATD and I found it locked in the full retard position, no wonder the old lady would not run properly!

As soon as I eased the pressure on the centre bolt the bobweights came free, all that seems to have been wrong is that the ATD had been overtightened on the taper so we’ll give it a try now before trying to disassemble any further.

While I had her up on the table I found that one of the rubber coolant pipes was leaking. The extra height let me see that the hose-clip on it was not on square and so the pipe was not snug onto the stub on the water jacket. Due to tight clearances it was a right flaff to get the clip on square, but that’s why it was on squint in the first place.

Fortunately it was the return pipe so I’ve only lost the header volume of the coolant, but I’ll have to top up the radiator before I can run her. Snag of a watercooled machine in winter, I’ll need to get some more anti-freeze and de-i water to top up with.

Then it was just drop the table and offload the bike. The table then pushed back to where it is stowed easily enough but I don’t fancy trying to move it with a bike on it, too bl–dy heavy.

As it is it sits between two bikes and the LE is run up onto it, the extra height means the LE’s handlebars and controls clear those of the other two and the combo fits in nicely behind it.

The snag I found with clearance at the front will only affect a bike where you need access to the front of the motor but it brought home the advantage of having a full length table rather than the cheaper option where the rear wheel is left over open air once you remove the ramp and of having sufficient width, I had seen one lift that was basicly a length of 6inch channel!. The one I’ve gone for has a 550mm wide table and would fit between two bikes in my shed but most I saw were in fact wider (and pricier!).

Timing Snags

Following a good firkle round on the LE Velo Clubs website and mining the data on their Forum I’ve come up with the information needed for checking the ignition timing.

Apparently on an LE it fires 29º BTDC. Considering that I have another side-valve boxer motored bike and it fires at 42º BTDC this seems a bit retarded but that’s what it says, both motors are just about square so it’s not that one is a longer stroke than the other.

There is also the fact that this equates to 0.26 inches of the piston down the bore as well as dimensions for the flywheel tool so this will help making up the special tools the book requires.

Only other thing needed is the extractor bolt for the ATD unit.

This is supposed to be available through the club spares scheme but is currently listed as “Not Available”, Typical!!.

From the picture it’s similar to the BMW tool for this job but the BMW one is metric threaded and will not fit, again Typical! as I have two of these!

Daft thing is that when I made the BMW ones the difficulty was in getting the correct grade an metric thread, now it’s the other way round as I’ll need a long high tensile 5/16 inch BSF bolt to make the Velo one and no-one keeps BSF stuff on the shelf these days!.

A possible snag here is that the tool has a long, slender tip, it has to be just under the core size for 2BA to go into the end of the crankshaft and that’s about 1/8 inch, it’s probably more practical to insert a suitable drill blank into a 5/16 inch bolt to make it as skimming down a bolt to this size on a big lathe is not the easiest of jobs.