Monday, 2 June 2014

A sunny day in June

My Square Four tank, and it does appear to be a Square Four tank (very large and of the appropriate width; large filler, pressure gauge hole) has as I said two taps (it also has a drain at front RH and no crossover pipe). What I neglected to mention (or even realize) was that the taps are forward of the tank mounts:

As you can see, on a Mk1 these are very close to the back of the rocker covers and will get frighteningly hot, I suspect. It looks a little odd; the closest reference I can find to this arrangement is a rather nice '51 KH shown in an article in RealClassic, which has two Ewarts taps in a similar location. The curious thing is, I have scoured all the KH and SQ4 parts books I can find and they all describe a single tap.

Hmm... Is this really a Square Four Tank?

So, one plan is to use a pair of Ewarts type plunger taps, 3/8" BSP into the tank with horizontal outlets. I will then make a copper/rubber tube assembly to tie the two taps together into the single inlet to the Solex. an alternative would be to blank the tap hole on the RH, and use a two-level plunger tap on the nearside - but I am not sure I have room for that.

I will need a supply of tube, nipples and gland nuts to make up this assembly - and I guess I will make a tee out of some brass barstock. I'm not sure where to buy these parts yet...

On a brighter note, she is a very handsome machine:

Max is nonplussed

Ariel do not seemed to have paid a lot of attention to the maintainability of their machines. Two maintenance items in this picture, neither of them easily accessed AND I have removed the kick start lever. More positively, the oil tank is now hooked up.

The valve timing is done, with a little help from my daughter - assembling the cam chain tensioner is not a one-man job:

And the exhaust pipes are looking good. The eagle eyed amongst you will notice the clutch dome is still off:

I have discovered however that when I straightened the RH footrest hanger, I straightened it too much and it now fouls the exhaust pipe.

More wiring done this weekend too. Horn and Lucas 529 rear light fitted:

and I am not sure what to do about the throttle cable abutment:


  1. Eagle eyed among us also notice the ignition coil, not to sound rude but are there any plans to sand and paint that thing in the near future? It does look a bit out of place on the bike and is definitely showing more age than it probably should when you look at it and the rest of the bike. Outside of that things are looking good, I'd be surprised if things aren't smooth sailing for you from here on out. No about those pipes, in the picture they look like you've got them permanently mounted however there should be a finned cuff that goes over them that compresses the pipes around the exhaust ports.

    1. Dead right Sypoth! that coil is a spare I was using to fab up the mounting bracket - the painted one is still hidden away. I have to tear that area apart again to fit a couple more bits - including the drive chain and it's guards.

      You're right about the finned exhaust clamps too - the problem is I only have one, and I am not convinced that the ones I can go and buy in the shops are the right shape. More on that later.

  2. Charlie, send me your e mail adress, then I'll send you some pics of the mounting of my coil, and the throttle adjustment. ariel4kees at

    cheers, kees