Friday, 15 September 2017

MZ Frame coming along

The TS125, in another part of Norfolk, is coming along slowly. This week, some reassembly and some painting.

Front mudguard:

Headlamp brackets and fork shrouds:

Here's the centre stand spring being stretch in time-honoured fashion

Back on the frame:

Spanners removed and the stand is back in action:

Fork yokes back in:

SQ4 - Oil Line Mod

I'm having a few issues with oiling at the minute, some of which are due to my own stupidity and some of which are not.

I have had persistent problems with the feed union to the cylinder head, which despite re-tightening on several occasions has always backed off after a few hundred miles. Seeking advice on this on the AOMCC forum, Nev Hunter from Australia pointed out that it was the fibre washer I was using that was at fault. This area gets so hot that it will cook a fibre washer...

In this location you must fit a copper washer:

The second problem was not of my making. There are two oil lines leading up to the cylinder head from the crankcase; from the front main bearing as shown in this diagram of the 4G, and from the rear main bearing, a banjo under the timing cover on later bikes. The assembly consists of two lines _ a 3/16" line for the gauge, and a 1/8" line for the rockers which seems illogical but the 1/8" line is there to choke the feed to the rockers and to maintain back pressure at the main bearing. Problem was, several assemblies are out there that are the wrong way round, which results in over-oiling to the rocker box and a gauge that under-reads (since the oil pressure to the rockers is lower), so we will set about fixing the problem.

4G Lubrication System

You need to take the tank off to have a look.

Here are the oil lines:

Here I've cut back the 3/16" line and fitted a 1/8" equal union, which will mate directly with the existing oil feed line:

Using the existing 3/16" rocker oil feed, I've fitted a 1/8" nipple & nut to mate with the old gauge line. In this picture, I'd kicked the engine over to prove I had oil coming out of those lines:

I took this picture after the first road test, when I discovered that the rocker box soldered joint had failed:

Saturday, 9 September 2017

Grease Everywhere

Some while back, on a very hot Norfolk Summer day, the SQ4 decided that the rear hub had had quite enough of that nasty, sticky grease thank you and vomited it all over the rear tyre and brake.

The trip home was rather gentle, especially as I had to descend from Norfolk's highest spot (!) to sea level, about 90 metres.

Pulling it all apart, there was grease everywhere. The parts washer is a very useful tool:

There are quite a few parts in the QD rear wheel, which is why I am writing this post. Here's an illustration from Draganfly, where we buy all the parts we need:

Putting wheel back together goes like this:

Put in the 4440B-50 grease retainer
Next comes the bearing. I'm using a modern double seal bearing, so we don't have a repeat of this grease leakage problem:

Knock the bearing in

Add the spacer 4346-50
Use a good quality peg spanner designed for the job, and the locking ring will go in easily. I've omitted the original seals, since I am using double sealed bearings.

Eagle eyed readers will notice the 4346-50 spacer is missing...

Locking ring trial fit
Turning the wheel round, we put in the 4471-50 Bearing Spacer Tube, whose smaller end locates in the 4440B-50 Grease Retainer. The Spacer Tube serves to allow the wheel spindle to pass through both sides of the wheel easily. The larger end of the spacer tube locates in another Locking Ring on the other side:

That's the wheel finished. Next, we turn our attention to the brake drum. Clean the bearing recess thoroughly, and include the slot for the circlip. I use Wagamamma chopsticks for jobs like this. Being bamboo, they are strong, flexible and be carved to the shape of the slot. When its all clean, press in the new bearing.

The pictures show the bearing in place, along with the 4440-50 Grease Retainer and the circlip.

Don't be fooled by this picture though, the fixed spindle comes next, with it's circlip.

With the grease retainer in place, you can fit the fixed spindle but you can't get the circlip in...

Thursday, 24 August 2017

There's always something

Having got the magneto back on, and the bike up and running properly, I went for a little ride... and it was great.

Back in the workshop, it was time to tidy up; while cleaning the oil draining trays out, I found this little chunk of cast steel:


Casting around for help on the AOMCC Forum, Adrie de Graff, from Holland, sent me this marked up picture of my own timing chest and suggested it was a bit of a cam follower.

This was backed up by the ever knowledgeable Nev Hunter, from Australia. I needed to investigate.

The cranked tin funnel came in handy again:

And with it all apart again, we could pull out the followers and have a proper look. This is the exhaust follower:

You can see in this picture that it is very thin around the cup:

It's a brittle fracture, with heavily discoloured material in the break. It's so thin, the case hardening would have gone right through the material. It's been like that for years.

So, Mr. John Budgen to the rescue:

I will be using the two on the left.

Wednesday, 2 August 2017

Vintage Motorcycle Club Forum


Another plug for the new Vintage Motorcycle Club forum, which is up and running at:

This is a great way to make contact with other vintage motorcycle enthusiasts the world over.

Mention Amelia's Blog when you sign on!

Sunday, 30 July 2017

Making a number plate

It's getting around to the time the W/NG magneto should be back from refurbishment, so we might be able to ride it soon. Time to make a number plate.

First, you need to find the right font. For our bikes, we need to print the number in Charles Wright Bold, 64 mm high letters. I used this site

You can type in your number, and the page will display it in the chosen font:

You want to size it to 96 points and capture it using alt-print screen; you can then paste the picture this creates into MSWord. You'll end up with a picture which you can stretch larger - resize so the letters are 64 mm high

Print it out in light grey, so you don't waste lakes of ink. Stick the print on coated paper; it's going to get wet, and you don't want your stencil falling to pieces. I used a discarded magazine cover.

Cut out the letters with a scalpel.

I made a bridge out of the letters to hold the middle of the '8', using double sided tape:

Apply the stencil to the number plate & retain with magnets. The dark shapes are pieces of broken magnet:

When I do this again, I think I will buy some of that magnetized sheet; then I can cut shapes that hold the stencil in place, or maybe I will cut the stencil from magnetic sheet...

Spray the colour of your choice. I used Ford Ivory White, left over from the Bantam tank panels.

Now, before the paint dries fully, remove the stencil:

Clean up overspray when the paint is hard. I used wire wool and Farecla G3 cutting compound:

It's almost there, but could do with a bit more cleaning up. What I like about this is that the ivory colour and the slightly uneven lettering fits well with the patina of the bike as a whole.