Eventually I found the indicator switch in a box marked 'Lucas SSU700' - which had no headlamp in it, but a complete set of Lucas indicators - which allowed me to finish the wiring in the headlamp, and put the wiring tools and materials away. All I have left is the speedo lamp, and for that I need the speedo back - oh, and the indicators work, save for the fact that they are currently fitted with 12 V bulbs. I've ordered some new bulbs.
The choke lever that came with the kit is not an original Amal lever - it looks like a Doherty to me, and it's pretty corroded:
The 1958 Amal catalogue shows levers with ball ends - fortunately I had one in a box of levers:
That's it for the bits and pieces jobs. Now I have this package from Draganfly - with these bits I can do the dynamo chain and close up the timing case, and I can finish and fit the rocker box.
Unfortunately those finned clamp screws are the wrong size - my fault, not Draganfly's, so if I can find some 0.445" hexagon bar in stainless I will make some.
Aside from fixing the horn, there were a few more little steps towards completing the Huntmaster today. The package from Draganfly arrived this morning and in it we have the throttle stop which goes straight into position on the twist grip:
There's a few more bits of wiring we can do as well. First off the BPF connector in the headlamp has poor quality wires and undersized bullets so we can replace those by desoldering the terminals, replacing the wire and adding some good quality English bullets for connection to the headlamp wiring. We can also add a splice and a couple of extra bits of wire to earth the BPF connector to the headlamp shell and onward to the main earth and the battery.
Additionally the pilot lamp holder was in really poor shape. The wire had started to degrade so it was really necessary to replace it. I used a small pop rivet to replace the terminal, and used a new piece of wire crimped into the pop rivet and provided with a bullet connector at the other end.
I just need to find a full set of LED lamps from Paul Goff to complete the work on the lights.
The last thing was to fit one of the pillion footrest rubbers. The other one is waiting on a repair to the screw retaining the footrest to the frame.
In a post a while back I wrote that given that I couldn't take the horn to pieces to clean the points and that as it worked, I would just go ahead and fit it. The trouble is once I'd wired it up, pressing the button had no effect. It just didn't work. I had it on the bench, checking the resistance of the coil with the multimeter and driving it with a bench top power supply but it was having none of it. It would have to come apart.
The difficulty with these horns is that the armature is retained in the diaphragm by a nut which is extremely tight. It's very difficult to remove, mainly because it's shallow and you have to be careful to hold the diaphragm to avoid it getting damaged. The way I resolved this was to make a wooden clamp that I could put in the big vice and hold the fragile diaphragm against the body of the horn whilst undoing the nut with a closely fitting tube spanner. With a 400 mm tommy bar, which I bent, it eventually came undone.
So that's the horn in bits. Once you've loosened the centre armature nut, you can remove the diaphragm leaving the armature in place. With the diaphragm off, you can slide the armature out from underneath the points assembly and that is about all the dismantling that you will need to do.
The point spring is very strong and it's helpful to use a jewellers screwdriver inserted between the moving point and the fixed point such that you can get a small sliver of wet and dry paper between the contacts to clean them.
Clean all the rust off with the wire wheel and Emery cloth. It's impossible to set the horn up properly if there is still rust on the body and inside the diaphragm and you won't be able to tighten the armature adequately if the nut is still stiff and rusty.
When you reassemble it, if you align these slots in the armature with the peg on the outside of the horn body you will have the armature in the correct relationship with the points assembly. When you have it in the right position you can tighten the nut up again using the same clamping mechanism that you used to undo it.
By the way, that peg is important. You'll note that the diaphragm has an inclined slot which engages with the peg? Well, the diaphragm can be rotated such that the slot causes the diaphragm to move up and down in relation to the body of the horn. This is how the armature air gap is set on these later HF1441 horns. The earlier Altette horns use a big grub screw and a nut on the back of the body for the same purpose. The diaphragm is held in place after setting with a clamping ring around the outside.
The easiest way to test the deflection of the diaphragm is to set the horn up on the bike with a magnetic DTI base sitting on some suitable surface, in this case the pillion footrest mount which on a PRF framed Ariel is quite flat. To test the deflection, back out the horn adjustment screw fully so that the points will not open when the push button is operated. Don't forget to undo the lock nut before you attempt to move the points screw.
When you press the horn button with the screw all the way out, you will hear the diaphragm deflect with a click. If you don't hear anything it's likely that the deflection is insufficient or non-existent so use your hand to increase the deflection of the diaphragm by turning the whole diaphragm anticlockwise slightly.
According to the Lucas instructions the deflection is supposed to be 11 to 13 thousandths of an inch.
When you've got the deflection correct, you can replace the clamping ring to hold the diaphragm in position. Then it's time to adjust the horn points setting: undo the locking ring and adjust the points using a small screwdriver. Turning the screw clockwise opens the points further for each deflection of the diaphragm.
You have to fiddle a bit with this screw to get the tone you want. Don't be afraid to turn it half a turn each way or more if necessary and test the horn each time until you get a tone that's consistent and doesn't sound like a dying parrot. When you fit the tone ring you'll hear it change substantially.
When you're happy with the sound you're getting from your rebuilt horn, don't forget to do up the locking ring, put the tone ring on and do up the acorn nut. I made this tool to turn the locking ring:
This will be the first time that I've wired up an aerial with the separate instrument panel fitted to the swinging arm frame bikes with the headlamp nacelle. Looking at the wiring diagram it makes sense to wire up the panel separately from the rest of the bike, to be fitted later.
As you've seen, and in line with the wiring diagram, I have fitted a 5-way bullet connector between the main harness and the front end. Some of the cables from the instrument panel will go into this multiple connector, and others will stay on the panel whilst further connections will go into the headlamp.
I made a start on the panel by fitting the ammeter and the light switch. I had the speedometer fitted as well, but found that the speedo lamp fitting was loose in the speedo body and the bulb holder could not be removed so I've sent this off for this to be repaired and the speedo overhauled.
Here's the initial layout. I've put all the wires in and crimped the ring terminals; the next step is to try this on the bike and see where the cable is going to route and how I can tie these cables together in sleeving.
This is the result. You can see I've terminated all the wires now, and added some sleeving and routed some of the wires around the top of the speedometer. I can't do much more until the speedo is back from Russell.
I need to clip the switch in and add the rubber ring around the switch and the ammeter, but it does work and I have both a rear lamp and a stop lamp. For some reason the horn doesn't work?
It's alive!
Next stop on the wiring list is to add the combined horn button and dip switch. This is the original one and I have just removed the old wiring and clean the switch up with degreaser. More of that later.
There's lots of little jobs around the bike getting on with. This one is the dynamo cork gasket which I bought from eBay. It was a little big and needed 3/8" taking out of the circumference.
That's the dynamo chain in place. It's got a split link which I think is unusual - but I think that this is the original chain. It's very difficult to tension because whilst you can turn the dynamo to tension the chain, as soon as you do up the clamp it pulls the dynamo back into the crankcase and loosens the chain again...
These are the clamps for the head steady. I've fitted them in place with some leather shim between the clamp and the frame to protect the paint. I'll leave these here for the moment until I have made the new studs for the rock box, and then I can fit the head steadies.
I bought all the cables as universal types from Draganfly. When I unwrapped them I was pleased to find the air and throttle cables were complete with their nipples fixed in place at both ends. Whilst the throttle cable fits ok, the choke inner cable is much too long so I will have to move the nipple.
These two pictures show the routing that I have adopted for the clutch cable. I've shortened the outer to suit this routing, and when the gearbox is back together I will fit the nipple.
I've made up two gaskets for the carburettor and the heat shield.
Perhaps inevitably, the throttle stop is missing from the twist grip. As soon as you slacken the cable these loose stops fall out and can be easily lost. I'll make one on the lathe later - perhaps two, one for the toolbox as a spare.
Edging ever closer towards first start, I diverted myself from wiring activities to time the ignition.
Regular readers will know the rocker box isn't fitted yet, and I can tell you that it's much easier to set the engine in position for ignition timing without pressure from the valve springs trying to restrain you.
As I've fitted 7.25:1 pistons to this machine, I am timing it to Cyclone specification - 3/8" BTDC at maximum advance in place of the 11/32" for the home market models. here it is on the ubiquitous Wagamama chopstick, of which I have hundreds:
The timing is set with the timing side piston at 3/8" BTDC on the compression stroke.
With the engine in the right position, I fitted my little clamp to hold the ATD at full advance. The ATD is screwed most of the way on, but is not yet on the magneto shaft taper:
With a green Rizla in the points, I can rotate the magneto until the paper just loosens in the points. It's useful to have a 4 BA spanner available to just hold the magneto shaft on that central bolt while you gingerly tighten up the ATD nut from the other side. With the petrol tank off, it's easy to reach the magneto from the timing side of the bike.
Next, fully tighten the ATD nut. You can then back the engine off and come back up to 3/8" BTDC; if the Rizla is just coming loose in the points (with the ATD still clamped to full advance), you are good to go.
