classic motorcycle forum

You don’t say what make of bike. I presume you mean BSA.

This thread is going no where. As in all these cases can we just have the engine and frame numbers? That would resolve the matter very quickly.

The gearbox number would also be useful.

Cheers,

Yes, as R says, a 123cc 9D Villiers for an Excelsior of the immediate postwar period 1946-48. You'll note the Excelsior has a hand gear change linkage that goes up through the tank and works in a slot in the middle of the tank. There's no particular advantage in this. It's merely a marketing gimmick so your 9D powered utility bike looks slightly different from what your neighbours are riding either side of you.
There was a 98cc version of this engine made pre war but they are easily distinguishable by their engine numbers starting either BB or BBA or BBS in the case of the Polish version made under licence from Villiers.
As you can gather I'm rather partial to these simple little workhorses. Sad isn't it but they make a pleasant change from the usual boring Triumph stuff.
Cheers,   

The “D” suffix denotes a revision of the crankcase seals arrangement on early 6E engines. It’s got nothing to do with gearboxes. It definitely has a 3 speed box as that was standard on all 6E. For that matter, once you have seen the 3 and 4 speed boxes side by side you will never confuse them again. It is very obvious.

In vintage times it was common practice to hide the spark plug in a deep hole away from the combustion chamber. As with every thing else back then spark plug technology was on its infancy and oil fouling was a problem. Plugs were positioned to avoid oil fouling and down a deep hole was a simple (and cheap) solution. Your ES2 engine was designed in the 1920's so is a relic from those days. Ride vintage bikes and you will often find spark plugs positioned thus and all working quite well. You can fit a long reach plug if you wish. Modern spark plugs are much improved over those from the 1920's It will make no discernible difference.

You've also received good advice about the timing. Personally I go along with Chaterlea25 I prefer his approach but that's just me.

Can we see a photo of the finished beast? I think the ES2 was at its peak in that plunger sprung frame era.  Lovely bike for just loping along at a steady 50-55mph. Like being on a steam train.

Locally, industrial felt is made in three grades and your seal is made from the hardest. One glance at the others and you will understand why.
Unless you have a remarkably well equipped workshop don't think you can cut your own. It needs to be accurate or it will be no better than the one you remove.
In my own case the firm not only provided the material but cut it as well. Not cheap, but accurate. If the firm has a minimum charge for the job see how many you can get for the minimum charge and you then have a few extra to trade or sell.
You don't say which S/A box you are working on but Chaterlea25's suggestion is the way to go if at all possible.

Best of luck.

I think you're right Per. It's mostly a bike built up of proprietary items. Most are a reasonable price. An Albion gearbox for example, won't break the bank. British Hub wheels are fairly easy to find.  The killer is the JAP engine. Even the cooking 250 ohv as used here is in high demand.  Nevertheless it is eminently do able and the joy of a Montgomery is that no one quite knows what is correct or not. From looking at the Montgomery in my shed its fairly obvious they were a small firm who used whatever was available. Some parts are very good, some are quite agricultural.

As far as the frame number is concerned the VMCC Register lists three Montgomery similar to yours. A 1936 model. frame number 92**. A 1937 with frame number 93** and 1939 with 95**. My entirely different 123cc Villiers powered 1939 model has a frame number starting 10***. I suspect Montgomery was so tiny they used the one set of numbers for all machines regardless of what model it was. Whatever they built that day got stamped with the next available number. The VMCC Marque specialist should be able to accurately date it for you.

Tanks aren't that expensive to have made. It's not the drama you may think. It's not as if it's a Brough or Vincent where every man and his dog will look at it and have an opinion. As long as it looks broadly like the catalogue picture, fits neatly and the handlebars don't hit it no one will know if it's slightly out here or there. If it looks right it is right.

Copies of catalogues are available from both BMS and the VMCC Library. Tank transfers are available.

It would be an attractive and smart little bike

Cheers,