W/NG - Crankcase lug repairs

I found a broken lug when I pulled the top front engine plate cover off:

Rooweld Engineering at Cromer made a nice job of fixing that. He said the casting was very clean:

In this picture, it just needs a touch more off the top of the lug for the engine plates to sit flat; the cases halves fit together nicely.

W/NG - dismantling the bottom end

Whilst it's tempting to think you are going to be able to lift the engine out of the frame without dismantling the engine plates and the footrests, don't bother. These bikes are so simple that you might as well pull it all apart. When you do, you can give it all a clean and attend to any problems you didn't know you had

First job is to get it all in the parts washer and give it a good clean. It's impossible to inspect anything if its covered in grease and road dirt

The crankshaft gear is a little stiff - you will need a puller to remove it. This one is made from a bit of 1" x 3/16" equal angle, with three holes and three bolts:

With it off, you can remove the crankshaft and clean up the cases:

I've put the crank in the vice to have a look at it. I think it needs a new big end as there is indeed up & down play and the side play is excessive.

A few years back I had the 'oil purifier' out. It comes out relatively easily this time:

Now that we have everything clean, it's easy to see what we are dealing with.

I've realised that as the flywheels are 8" in diameter there is no way I can contemplate truing them in my lathe, so they will have to be sent away for repair. This is going to be expensive.

Model A - bits arriving

The Model A kit has advanced a little - I've got the clutch and air/ignition levers, both correct original parts, from eBay. These are not cheap! 

There's also a 5" D section front mudguard under there. 

W/NG - time for some serious engine attention

As some of you may know, the W/NG hasn't been too happy recently - it's been consuming spark plugs at an alarming rate and has caused several unscheduled stops by the roadside - particularly annoying, because I'm lucky enough to live by the sea and a bike is the best choice of transport in the summer - you will never find another parking spot for your truck again if you choose to move it.

So, the W/NG is the go-to machine for local use, until it decides it isn't going to play nice any more. Next up is the SQ4... which has a flat battery and knackered points (my fault - embarrassing story), so now I know what a garage full of dead Ariels looks like:

So I've pulled the W/NG apart.

The rocker boxes come off easily. There is some head damage around one of the bolt holes, which I will probably leave well alone:

The piston is an oily mess and the top ring is in three pieces:

The small end is cratered but is dimensionally OK. I've not measured the pin or the piston yet, but the bore is 2.871 in the middle of the stroke (fore and aft direction) which is getting on for 40 thou over factory standard. There is no ridge at the top, so we will have to see what the piston dimensions are.

The valve guides are awful. I've not measured the valves yet, and I have no way to accurately measure the guides but the exhaust valve rocks maybe 1-2 mm at full open, the inlet maybe half that. The inlet guide is loose.

Then there is the big end. I can feel up and down play of maybe 0.5 mm; side to side rock is maybe 3 mm at the small end.

All in all, a good afternoon's work. A lot nicer than the morning, which was spent pulling one of these apart: