Charlie's Shed - Petrol Tap Filters

Updated from December 2017

Many of the fuel tanks we have on our bikes are not in the best of condition and may be flaking rust or paint from inside, or worse, your tank liner may be in the process of falling to pieces. It's essential to have a good fuel filter.

Here are a few I made earlier:

Most of the fuel taps I have acquired have had either missing or holed filters, and, having had very limited success with the inline filters on the market (poor fuel resistance in plastics leading to cracking & cloudiness, or a ridiculous flow coefficient leading to fuel starvation) I have set about replacing the missing in-tank filters. This is typical of the damage you will find, if not a lot worse:

These are pretty simple to make if you are reasonably adept with a soldering iron. Start by removing the old one. I use a kitchen-type blow torch for this, which is plenty hot enough for sweating soft solder:

Hold the intake tube with a pair of pliers and twist it gently when the body is warm. It should come free quite easily

Look for the finest mesh you can find. The originals are a very fine copper mesh which is easy to obtain (though the mesh in the pictures is actually brass). Cut a suitable rectangle with scissors.

Start to form the cylindrical shape around a pencil.

You'll see that the final size for the filter on this double-plunger Ariel tap is very close to the diameter of an AAA battery:

I use a chamfered edge on an old credit card to form a tiny lap joint on both edges of the gauze, like I did with the oil strainer on the SQ4:

I then roll them around, mating up the lap joint and folding it down tight on the AAA former.

You can make a simpler lap joint like this:

Solder the joint with a small iron:

Flare the end to fit into the recess on top of the tap:

Have a good look at the recess on top of the tap. Make sure you clean out the joint of all goop, old fuel, rust and old solder. We are going to tin this area and sweat the new filter in.

Put the main feed pipe back in and trial fit the filter:

Now, push your AAA battery former up to the other end of the filter and form the closure:

Lay some solder onto the flare:

Lay a little more solder onto the end closure:

Flux the top of the tap and using a small blowtorch (the type you might use in the kitchen) apply some solder all around the joint, without the filter in place. Let it cool and clean it up and have a good look to see that it has run all the way around, then add the filter. Reheat the tap just sufficiently to melt the solder , and the heat should transfer to the solder ring around the filter flare allowing the two to fuse.

You might notice that this tap is fitted with a 3/8" BSP Dowty seal - makes a better job of sealing that joint than a fibre washer.

If you still have problems with your tap, check my post on replacing plungers here.

Thanks for reading, and I hope you found it useful.

Starting Young - Honda QR50

It seems to be a year for buying old red Hondas. First the 1978 CX500, now this:

Under that horrible red poster paint is a Honda QR50 from the early 1980's (initially I thought 1983 - overhauling the seat revealed the seat cover was made in 1988) which is a mini-crosser with Honda Express running gear. One day it may look like this:

It looks pretty scabby, and it looks like the rear suspension has collapsed. It is now in a pile of bits, but over the next few months son Thomas and I will get it ready for my grandchildren to ride!

There's an extra tube in that sub-frame

Break out the paint stripper!

Who cuts a chunk out of a tyre? no wait - I've done that myself. Must be rock hard

That cylinder head looks toast...

Why O why do people insist on stripping the engine and then leaving it for years?

This is the engine/transmission unit, assembled - not ours, a reference picture from Google. You can see the two 'swinging arm' bearings behind the cylinder:

Excellent parts lists here:

https://www.cmsnl.com/honda-qr50-1983-d-european-direct-sales_model19626/partslist/

CX500 - Indicator Stems on the Mini-Lathe

Updated: First published 24th June 2019

The latest family acquisition is this 1978 Honda CX500, bought from eBay by son Thomas, and a very fine machine it is too.

The previous owner was, like me, quite short and had lowered the seat producing a very strange riding position; Tom has fixed that now with a new foam and cover.

You can see from the previous pictures that the bike is missing it's grab rail, which includes the proper mounts for the rear indicators and the tail piece. It's absence means the tail piece wobbles and the indicators don't earth properly.

So, a new grab rail appears from eBay but we need some indicator mounts. The ones fitted to the grab rail are wrecked:

We'll make some new ones from a stick of 19 mm grade 303 stainless round bar I have knocking about. We'll start with the end with the bolt recess:

I've drilled this part way through, 6 mm, for the indicator cable.

Then we'll swap it end for end in the collet chuck and machine the smaller diameter, which fits in two top-hat rubbers in the grab rail. We'll need a 10 mm diameter for the thread retaining the stem into the grab rail:

We'll thread these in the tailstock dieholder:

The tubes that carry the indicator stems have a small tongue, to stop the stem turning. The stem has a slot to receive that tongue which we can mill out:

That's two done, ready for the splines:

We'll cut 45 splines to match the original, using a tool ground at 80 degrees and taking 5 thou cuts to a depth of 15 thou. Here's the setup, using the indexing attachment I made; the lathe is used like a shaping tool in this configuration. The machine is out of gear and the E-Stop is locked off.

Here's a close-up of a few splines, cut to depth:

Here are the two stems, with splines complete and polished up with some 240 grit emery.

Next job was to turn up some isolation bushes in black acetal:

And here's the first one fitted to the grab rail:

And with an indicator test fitted:

Pillar Drill

I've had a small pillar drill for about a year, and pretty cr@p it is too - but it was very cheap and it's a whole lot better than what I had before, which was a hand-held power drill in one of those bench stands.

This one works well enough, it has the usual stack of five pulleys and belt drive, belt tensioner, convenient power switch etc and you can set the table at an angle. But it is very flexible - the base and the table are pressed steel and the pillar is very thin - the whole thing will bend when you put any feed on.

The spindle is mounted in sealed bearings but once the quill descends it has quite a lot of play.

Here's the depth gauge and guard - this is hard plastic and broke almost the first time I used it. The depth gauge requires you to fiddle with those two nuts:

I decided to make a new mounting for the guard and depth gauge, but mostly because I want to do some boring in a big-end type arrangement (like a locomotive eccentric strap). The new mounting is made from two lengths of 10 x 30 mm aluminium bar, screwed together with two M4 screws and shaped to match the old one. Here, I am aligning the components with the lathe centre prior to drilling and boring a 40 mm hole to suit the journal on the pillar drill. The two halves of the clamp are spaced 1 mm apart, so they clamp securely to the drill:

Here it is in place, along with the broken bits of the original:

Mini Lathe Updates

Readers might be interested to know that the mini-lathe page:

https://ariel-square-four.blogspot.com/p/mini-lathe.html

has been updated this week, with a few new bits:

• a 3D printed apron gear cover
• a modification to the tailstock die holder

Thanks for reading, and I hope you find it useful.