SQ4 - a little investigation

 Of course, a broken motorcycle can’t be left for too long, especially when your daily rider has been persuaded from your grasp.

There were a few problems to investigate, possibly associated:

• There was a carburetter leak, or possibly flooding 
• The battery indicator was showing far too much red, considering the 60 miles the bike traveled yesterday 
• The bike refused to start twice yesterday, needing pushing to the top of a hill and roll-starting 

Putting the CTEK on the battery had it charging normally, but it was very flat:

But why so flat? According to the ammeter, the battery does charge and indeed, it was charging on the way home. I did notice the ignition had been left on as Tom had complained the engine wouldn’t idle and it had died when he arrived. I currently believe this has more to do with the battery than anything else.

There is no leakage from the battery with the engine not running and you can measure normal currents with lights on, though with the LEDs fitted to this bike these are minimal. The ignition circuit draws 400 mA without the engine running - I think it would be a good idea to try this with the engine running.

I've also realised that the red spot ammeter doesn't show very much deflection at all - I calibrated the one on the Huntmaster against my bench power supply and there is a lot more movement. I wonder if the Square Four has a 30-0-30 ammeter.

A simple test with a 35 watt bulb revealed that the ammeter appears to be 15-0-15 - while I was doing this test the multimeter was reading 5 amps.

As a first step towards sorting the fuel leak, I removed the drain plug/main jet holder and finding no new fibre washer of the right size, sealed it with a wipe of Threebond 1215. That fixed the leak, and there is no evidence of flooding. 

Amelia started first time like she always does.

As to the idle, I don’t know yet as I haven’t got it warm enough to close the bi-starter.

Model A - Lucas E3 dynamo

So what's next? With the kickstart done and the gearbox back together, my plan is to reassemble the primary drive to get the bits off the bench, and move on to the front forks - a big unknown. They didn't have bushes in 1930, so we are looking at a machining job at home or away. To get there though, I have rebuilt the clutch and next is the primary chain and covers, which just need paint. I'd like to reassemble the dynamo and it's drive, but it's toast. I could either:

1. leave the dynamo in a box for a few months and get on with other things
2. reassemble it mechanically (the body needs replating)
3. Fully restore the dynamo

I've got no nickel plating chemicals, and I have a long list of FH bits that need plating which I don't really want to get into right now (and as of this afternoon, my son has taken the Huntmaster and left me with the Square Four which won't idle...); I don't want to leave the dynamo bits in a box for months, so we will go for option 2. I've also seen at least one picture of an E3 dynamo with a painted body - and I've seen another picture of a 1929 bike which made me realise that you can't really see the body when it's mounted on the bike!

Here's a photographic survey of the dynamo:

In the picture above you can clearly see the damage done to the armature - it's thoroughly bent and unrepairable. Notice that this early E3 has the magneto type open ball bearings and the taper fit for the driving sprocket along with the male thread for the retaining nut. Characteristically, the armature is 157 mm long. Putting all this together enables us to purchase a new armature for this 36 watt dynamo.

I've ordered this repair kit from Rex's Speed Shop which will include the proper bearings:

As I may have mentioned, this is just going to be a photographic survey for future use. Here are some views of the dynamo body and the commutator end casting:

Close up, we can see that the other dynamo and casting has been a victim to the side swipe that this bike has suffered - there is a crack in this end as well. It looks repairable though:

SQ4 - a ride out

 My son made a surprise visit today to borrow one of my CTEK battery chargers. He's not seen the Huntmaster yet and we agreed that I would ride with him halfway home so that he could have a go on it. He was very pleased with it.

However, when he arrived on Square Four he was complaining that it wouldn't idle. I noticed that he'd left the fuel on and the ignition on, and the battery condition light was showing red. I got it started by bumping it down the hill and rode it to North Walsham; it was okay ish but it obviously wasn't happy at low engine revs - but it was charging.

After a bit of a chat at the North Norfolk Motorcycle Museum, I left to go home but it wouldn't start at all - the carburettor was dripping and the battery condition light was still showing red which suggests the battery is not holding a charge. Again I'd left the fuel on, so maybe it was overflowing and the float valve is not working properly, or maybe there's a leak. 

Eventually I got it started by rolling it downhill and and rode it home like a bat out of hell at up to 60 miles an hour. It was charging, and going fine and I got home safely though the front brake is a lot worse than the one on the Huntmaster. 

I put it on the battery charger when I got home and the battery condition light showed red for several minutes, which is unusual - normally if I put it on charge it will go to green straight away. After a couple of minutes it went to solid green which means it's charging or fully charged.

There's something wrong here.

Model A - Sturmey Archer clutch

 I feel like I am in a bit of a vacuum now that the long running kickstart shaft machining project is finished, so I will pick up the easy option of tidying the workspace while identifying something to do from amongst the myriad of jobs. The first one that springs to mind is the clutch which has been laying about underneath the bike.

It's in pretty good shape but it had a couple of bits missing that I have replaced over the last few months so today I'm going to strip it and clean it up before reassembling and fitting it back on the bike. I will then rebuild the primary side and put the chain cover back on - I will paint it if it's warm enough.

With a bit of help from the Raleigh owners club I learned how to strip it down - it's all down to ten 1/4" nuts which are uselessly staked in place.

The shock absorber looks very good and I am tempted not to replace the rubbers but disassembly of the clutch centre does not go quite according to plan and I end up with balls and rollers all over the place!

There are 17 rollers and 16 balls here, exactly as per the parts list but I didn't really understand why you would design a bearing with mixed balls and rollers. The combined intellect of the Raleigh & Ariel Owners Clubs taught me that the rollers are there for axial stability, but the balls reduce friction - the idea being that the ball to roller friction is less than the roller to roller friction would be.

A sample roller measures 0.250" diameter by 0.249" long and a sample ball measures 0.249" diameter. I shall replace them all.

Cleaning up the clutch centre reveals this little hole, with a partner on the opposite side. Are these intended to allow oil to be introduced into the bearing? Or are they drains?

A couple of hours with various wire wheels and brake cleaner brings the parts up very nicely for inspection, but there is little damage.

I have a couple of new spring cups from the Raleigh club and a set of new springs, plus the two new clutch springs screws that I made a few weeks ago. Currently these have standard quarter inch washers but it is noticeable that the originals are very tight on their screws so we will make a couple of replacements on the lathe, from this bit of 3/4" round bar:

I've just parted off a couple of washers to match the length of the original ones. We will chemically black these later.

Next up, it's a bath of thinners, the wire wheel, and a dose of Scotchbrite to bring the plates up. They all have a bit of burring on the tangs so we will have to dress those with a file.

Saying that though, I think it's probably more important to look at the basket than the plates. I'm convinced that burrs like these produce more resistance to free clutch plate movement than the burrs on the plates: 

Model A - that kickstart lever again

 Well, yesterday it was finished. The cotter pin went in way too far and would need replacing, but it worked. However, there was an itch...

I suppose I am a bit obsessive, but I couldn't put up with having to remake the cotter because I had machined the shaft wrongly. I filled the slot up with weld.

A few minutes later, I had re-machined the slot; the shaft is 3/4" within the kickstart lever and the slot has a maximum depth of 0.150" - the easiest way to measure this accurately is from the bottom of the cotter slot to the opposite side of the 0.75" diameter, so you measure 0.600". The slot is bang on the correct depth, and the 0.375" cotter pin fits perfectly.

All I need to do now is cut the spare length off the cotter pin and radius the end, like this:

Now it's finished. Definitely. Apart from the spring cover...

Model A - fitting the kickstart lever

 The last step in the long story of the kickstart shaft project is to machine the flat for the lever cotter pin. We are back on the lathe with the vertical slide and will use this setup to machine the slot:

The cotter pin is about 3/8 diameter so we will use this 3/8 end mill to cut the slot.

This is the last pass of 3/8 end mill - and it's a pass I wish I hadn't made. I was very near the end and used a trial fit to find that the slot I was milling was about 1/32" too shallow. For some reason I decided that it would need another full turn of the lead screw to finish the cut - completely forgetting that the lead screw pitch is 1/16". So now that slot is too deep.

I could weld this up and re-machine it, but the cotter pin still fits and stays in place properly. I guess I will leave this until it becomes a problem - I can't get a 3/8" bolt in there, which would be possible if the slot was any deeper.

So for now, the kickstart shaft is finished.

Model A - layshaft bush

 With the kickstart shaft nearly finished, we need to think about the bush for the lay shaft. This fits in a bore in the end of the kickstart shaft: 

The bush will be a top hat shape to accommodate the end of the layshaft and to determine the end float of the low gear pinion. It's going to be made from this piece of SAE660 bronze:

First job is to reduce the diameter to nominally 1” to pass into the shaft with a few thousandths clearance:

Next, we reduce the diameter such that we have a few thousandths interference fit in the 7/8" bore, and add a small chamfer to aid assembly. That done, we can bore it in steps up to 5/8" - our shaft is 11/16", but we will do that last bore in situ.

Parting off the bush. The hang out here is not ideal at all, and I believe I may have knocked the stock out of square in the chuck - it would have been far better to do this job with the revolving steady.

No matter though, this does not affect the working diameters and we can face off the end of the bush if necessary.

The top hat bush, mostly finished aside from the layshaft bore.

It's not as tight as I would have liked, so I have fitted it with Loctite 603 retainer. This won't be cured until tomorrow.

This is the last job for the lay shaft bush - it's been fixed in place and the Loctite has cured overnight so it is now being bored too 0.6875" for the layshaft. Notice that the shaft is in the fixed steady - it is essential that the shaft is bored concentric to the kickstart bush in the outer gearbox cover:

Some while back I had left a little excess material on the major diameter of the shaft thinking that I might need to play with the first gear pinion end float, and so it proved. As machined the shaft is a little overlength and I used this setup to remove around 0.020" from the end of the shaft which provided the necessary clearance. 

I'm pleased to say that assembly and testing of the gearbox proved that everything works as expected. The next step, and final step, is to machine the recess for the kickstart lever cotter pin.

Model A - fitting the kickstart pawl

 Back home after a few days away fitting a new front door and frame at my daughter's house in Kent, I find a few minutes to move the kickstart shaft project along a little bit. 

When I left a few days ago I had the shaft set up in the pillar drill just waiting for final adjustment and the fitting of a centre drill to start the hole for the pawl.

That done, we move on to the 9/32" hole on the outside of the shaft. I have discovered that the pin is retained in place by the low gear pinion and cannot come out in service. I bought a pair of long series drills for this job and it makes it a little easier to set the work up on the pillar drill. We go right the way through both sides with this one:

We follow the 9/32" with a 5/16" drill which only goes through the inside web. I'm pleased that the pin fits very well in these two holes and with a little fettling (the pawl was rather ragged) the pawl goes in as well.

I'm a bit concerned by the shape of the pawl where it engages the pinion as the surface, perhaps not surprisingly, is rather worn. A further problem is that the cam which pushes the pawl back into place actually jams the shaft. This is due to the lack of wear in the new shaft I think since dimensionally it is identical to the old one.

Working on the pawl a little to square it up and refine the edges sorts out the problem and we have a pawl that goes nicely into the retracted position:

The video shows it working in both positions:

A dose of heat and a pot of case hardening compound will give us a pawl that fits and has sharp edges giving it plenty of life. We'll have to see if it still works with the bush in place - that might require a bit more fettling, so we will leave the case hardening until that is done.

Model A - positioning the kickstart lever

 As we get towards the end of the kickstart shaft project, it's time to think about where the lever will sit and where the flat for the cotter needs to be machined. This picture mocks up what it will look like eventually: 

The key to success here is to understand the relationship between the mating face of the cotter and the flat on the shaft, all of which combine to determine the position of the lever. The last thing we want to do is to have the lever too vertical or too low in relation to the rest of the machine - worst still that it sits forward of the gearbox! 

We'll use the old shaft to understand this relationship.

What you see here is two pictures of the lever, the cotter and the old shaft. I have used a Sharpie to show the relationship between the shaft and the lever. 

We can see that the cotter fits in either direction without affecting the relationship between the shaft and the lever. 

This next rather blurred picture - it looks like it's focused on the bench top - shows the Sharpie mark against the flat on the old lever and confirms that the flat is perpendicular to the axis of the lever. 

We can use this information when we machine the flat on the new shaft. We'll have a look at some of the reference pictures and get a feel for where the lever should be.

Model A - this is getting boring

 While we wait for the long series drills with which we can finally fit the kickstart pawl, we can look at preparing to drill out for the layshaft bush and for the relief drilling that will clear the layshaft first gear pinion. I need to do some measuring to ensure I understand the various dimensions that will be required, but I know that the bore to clear the pinion will be in the region of 1" diameter.

You will recall that in a previous post we machined off the flange that had been used to hold the shaft in the rotary table, reducing it until it would pass through the fixed steady. We see it in use in the picture below during setup:

The short 5 mm hole that has been used for the revolving centre is opened out progressively until we run out of twist drills. This is the 10 mm drill passing right through and into the body of the shaft:

And here it is opened out to 7/8", which is the largest drill I possess - it actually has an MT2 taper and fits directly in the tailstock:

The next job is to part off the stub, but sometimes it is easier to rethink your approach to a job. I set the lathe up to part off this stub after I moved the fixed steady to the 1 1/8" section, but actually I realised it would be much easier to saw it off:

That took less time than setting up. The orange dust is from the saw blade!

This rudimentary sketch shows us what the dimensions of the hole need to accommodate. As I have no wish to bore the hole to over 1" all the way into the shaft, reducing the wall thickness just where it needs to be strongest, I will make a stepped bush to accept the layshaft and provide a thrust face for the low gear pinion. This will be 1" or thereabouts at the inboard end, and reduce to 7/8" for most of it's length. This will give a thin wall over most of the length of the bush since the shaft is about 11/16".

That's the bore done for the low gear pinion - it's 1.010".

I used a depth micrometre to determine the dimensions of this hole - it's a nice tool that I bought from someone at the railway a few years ago:

The whole has two diameters - one for the layshaft and one for the low gear pinion. Both of these diameters will be bushed:

The larger of the two fits the low gear pinion beautifully:

The smaller one clearly fits over the layshaft:

We can also see that the length of the 1 1/8" section is just right:

Now we need the bush, but before we make that the package from Tracy Tools has arrived with the long series drills we need to fit the kickstart pawl and it's pin but before we do that we'll spend the day driving one of these: