FH - pillion footrest

This post is to show you how the most simple small problem takes up and inordinate amount of time. You will remember that I mentioned that one of the pillions footrests was damaged and that the screw wouldn't go in. Here's the footrest mounting I'm talking about:

There is or appears to be a burr on the left hand side of the hole. Actually the whole footrest mount has suffered an impact from the left and the hole is distorted. I spent some time with the Dremel and a small grinding bit removing the burr and relieving the hole on both sides. The screw still wouldn't go in and I resolved to take a slightly different approach:

The new approach was to take the screw and stick it in a collet in the lathe and relieve the diameter of the head by a small amount, leaving the original diameter on a millimetre or so of length so that the outward appearance wouldn't change. This allowed the screw to go into the distorted hole, retain the footrest, and for none to be the wiser.

 

FH - HT leads and plugs

 The FH is going to be fitted with a pair of Champion L82C plugs as an equivalent to the Lodge HN originally fitted. The rubber plug caps came with the refurbished magneto.

The HT leads, copper cored rubber, are the same length on both pickups. As I haven't consciously timed the magneto to a particular cylinder, they may be the wrong way round.

We will leave cutting them to length until we have it running.

FH - engine finished

 Yesterday I spent a bit more time attempting to finish the tappet covers. After clearing the threads in both the covers, clearing out the locating pin holes and straightening one of the locating pins on the inlet I finally got them to fit. The part numbers are identical for both inlet and outlet covers, but for some reason the one I had on the inlet fits the outlet and the one I had on the outlet fits the inlet. Go figure. There's obviously something around the locating pins, and I did notice that the original centre screw is longer than the one that I made; however, they are both on and done up and finished. 

Next I moved on to the timing cover with Wellseal and grease either side of the gasket as this cover comes off fairly regularly. 

The dynamo chain area is now liberally coated with semi-fluid grease and the cover is on. Some of the screw holes are obviously not clear for their full length and now that I have new Acme stainless steel screws I will need to run a tap through some of those holes again. I've ordered a tap from Tracy Tools - they do a very long (and expensive) tap called a 'nut tap' which will do the job nicely. 

The 'nut tap' is a very long taper tap - I'll need to cut perhaps half the length off the taper, as I really need it as a plug tap.

Next step is to close up the gearbox. I'm on the railway for the rest of the day, so that will have to wait until tomorrow.

One job I haven't really finished is the head steadies. Unfortunately despite the fact that they are retained to the head with half nuts, there is still not enough room to get a nut on the timing side - the drive side has a fin missing. It's extremely fiddly in there, there is no space, and unfortunately I have realised that you have to have the rocker cover slightly high before you can get the nuts on. I'll lift the rocker cover again next time. 

FH - tappets done

 Just for the record, this morning I have set the tappets on all valves to 10 thou.

The toolkit is going to need a 10 thou feeler gauge and a 1/8 hex key.

FH - dynamo chain

 In 60 stolen minutes (home early from a turn on the railway) I had an opportunity to do something on the Huntmaster. My initial thought was to set up the tappets and I had a look at the tappet cover locating pins to see what was going on with the inlet side, which doesn't fit. This job was going nowhere without a bit more time so I looked for something else to do and settled upon the dynamo chain. 

I removed the dynamo driving sprocket successfully with a small puller but I couldn't remove the driven sprocket at all; however, that was enough to allow me to put the new chain on.

For the record the cork gasket behind the driving sprocket is definitely there:

The new chain looked a bit larger in width than the one that was originally fitted; I've kept the old one just in case. The new one went on without any problems followed by the driving sprocket with a new tab washer - folded up here again for the record:

I'm a bit puzzled about the driven sprocket, which is a castle nut and has a hole for a split pin in the shaft. However, the slots in the castle nut don't fall in alignment with the hole due to the width of the sprocket and since it is fitted with a tab washer per the parts list, this is obviously correct. The tap washer is bent up correctly:

I really ran out of time to put the timing cover back on, but we'll do that tomorrow.

In the meantime, there's a curious little puddle underneath the oil filter - perhaps it's loose. Another little problem to take a look at!

FH - wear in the valve train

 Last time we were here, I wrote about some wear I detected in the valve train through not being able to set up the valve clearances properly. What I've done now is remove the rocker box again to have a close look at the tappet adjusters and the push rods. 

Removing the push rods and measuring them revealed that the inlet pushrods are correct to the measurements shown in Draganfly's pages of information. Strangely enough the exhaust push rods are actually slightly too short, which is unexpected since I was able to set up these valve clearances easily.

I also measured up the tappet adjusters. I made some posts on the club Facebook page about both the tappet adjusters and the push rods which revealed some useful advice from fellow members. It appears that the tappet adjusters are more or less the correct length, however the later BSA or Triumph adjusters (which are the same length and thread, 5/16" CEI) are provided with hex socket heads and are consequently easier to use. Looking closely at my original Ariel adjusters showed that the square heads were deformed slightly and would not go into the lock nuts, limiting the adjustment available.

I resolved to take the club member's advice, and bought a new set of adjusters and lock nuts.

Further advice from a gentleman who races Ariels had me looking at the extent of the heat treatment of these adjusters. Some of the ones on the market are apparently prone to breaking around the hexagon socket due to over hardening in that area; it appears that the extent of heat treatment on the ones I bought is limited to the area that makes contact with the valve stem, so that should be all right. Hopefully...

Today I fitted the rocker box again, with a longer bolt inside the inlet end. This is a much better approach than the stud and nut that Ariel specified (you will lose the nut down the pushrod tunnel) and is actually a BSA approach to fixing the rocker box shown to me by Steve, a long distance Huntmaster rider. 

Unfortunately tightening the rocker box bolts revealed that the nuts in the two rear corners could not be fitted with the box fully down. I loosened the main bolts and jacked up the rocker box using the inlet valve adjusters high enough so that I could get the reduced hex nuts in place on the rear corners without losing the pushrod location in the rocker cups.

That done, it was time to pack up for the day but not before I had temporarily fitted the rocker box covers and one of the head steadies. One of the rocker box covers doesn't fit very well due to burring on the locating pins which I'll have to fix later.

Here's a wider view of the engine, with both exhaust pipes temporarily in place:

Next, we can finalise the valve clearances, which are 0.010" for both inlet and exhaust; these new Triumph adjusters need a 1/8" hex key, one of which will have to go in the toolkit. When that's done, we won't need to have the facility to turn the engine easily, so we can close up the gearbox. Before I do that I will fit the pear nipple on the clutch cable; I'll adjust the inner clutch cable length later as I want to replace the handlebar end nipple with a brass one. I'll do the air lever nipple at the same time.

Offline from all this I can replace the dynamo chain and fit the timing cover. Then we can seriously think about first start.

FH - rocker box

It's pouring with rain here today so badly that I can barely take the dogs out, so I've taken a little while to come and varnish an oak window sill and fit the rocker box to the Huntmaster. 

We start with Wellseal on the rocker box gasket faces and stick the gaskets in place. Next we'll put another coat on the cylinder head gasket faces and manoeuvre the rocker box into place over the pushrods.

I'm using a small USB camera connected to my phone to have a look in some of the small spaces around the top of the engine. The camera is small enough to go down towards the pushrod tunnels so that we can verify that the bottom end of the push rods are sitting in the tappets properly.

The camera fits through the inspection hole in the top of the rocker box and through the big spaces at the front and back to allow us to see whether the push rods are engaging with the rockers properly. You can get a small screwdriver in front or rear to nudge the pushrods into place.

With a bit of fiddling, I got the rocker box down and bolted. These bolts are actually supposed to have shakeproof washers so I shall have to change them later but the gaskets are pulled down properly. I've also fitted the rocker box oil lines.

So this all went pretty well except for one thing. Whilst the rocker box is down and I've managed to adjust the exhaust rockers to a reasonable clearance, there is no way that I can get the adjusters far enough into the rockers to bring the inlet rocker clearance to specification. I'm not sure what's wrong with this, it might be worn adjusters, it might be worn pushrods...

Wish I had had the foresight to measure the pushrods before I started...

FH - a bit more done

 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.

FH - baby steps

 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.

FH - that horn again

 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:

FH - wiring the dashboard

 This will be the first time that I've wired up an Ariel 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.

FH - various jobs

 There's lots of little jobs around the bike to be 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.