belt and oil pump 2 3/4 HP

[andertheke]

Hi Experts,

I'm trying to bring my 2 3/4 HP back on the road. The endless belt between gearbox and rear wheel consits of little segments.
Some Questions:
1) what have I to do to release this belt? Which screws have to be released?
2) If I want to order some spare segments, where should I size to find out the exact item to order?
3) how is ist possible to remove every single segments? Do I have to use a Special tool?

One Question About the oil pump:
4) When starting is it enough to pull the oil pump to its top and the automatical oil drops work fine or ist there any plug which should be opened?

Thank you very much for Your answers!


Hallo Experten,

bin nun dabei, meine vor geraumer Zeit erworbene 1914er Douglas 2 3/4 HP auf die Straße zu bringen. Bezüglich des aus lauter kleinen Segmenten zusammengesetzten Riemens beschäftigen mich folgende Fragen:

1) Wie entspannt man "alles" so, dass man den Riemen herunternehmen kann? Also an welcher Stelle muss was gelöst werden?

2) Wie/wo muss man Messen, um herauszufinden, welche Größe die Segmente haben, aus denen der Riemen besteht, um ggf. einige Segmente nachzubestellen?

3) Wie genau muss man sich anstellen, um einzelne Segmente herauszulösen? Benötigt man ein Werkzeug? Reichen geschickte Finger?

4) Genügt es, die Ölpumpe einfach nur zu ziehen und es tropft los, oder muss irgendwo ein versteckter Hahn geöffnet werden?

Besten Dank für Eure Antworten



Image rotated - Dave 15th July

[graeme]

Hi
The belt is the type known as a "Brammer" belt. I am familiar with this type of belt, having used them in the past. To release the belt you need to work the belt off the rear belt rim, these Brammer belts stretch so much in use that this is normally not at all difficult! Then with the tension taken off the belt, to get the segments apart you simply bend the belt with your hands so that the pins can be released from the slots in the segment, the pins passing through 3 segments.
I ended up giving up on this type of belt, getting sick and tired of having to remove segments every time I rode the machine! I now use endless belts made by Opti, they are C section and are available in 1 inch increments, so there is no trouble getting the correct size.
As for the oil pump, yes you give the plunger a pump and the oil works it's way past the needle valve and drips down into the crankcase. You obviously need to adjust the needle valve to get the correct rate of oil flow, equating to about a drip every 3 seconds at a road speed of around 50kmh, a bit more if the machine is working hard pulling up a long hill for example.
I hope this helps.
Cheers, Graeme

[andertheke]

Hi Graeme,
thank you very much, for Your very helpful answers.

I'm not sure, which screw should I release to release the tension of the belt to work the Opti belt on. Gearbox doesen't work, because of the chain an the rear axle seams to be fixed in one position.


Best regards
Peter

[eddie]

The rear end of this frame is somewhat unusual - it has the later stand mounting (below the rear fork) but still has the upper stay welded to the rear wheel lug (rather than bolted on).

  Eddie.

[andertheke]

yes the front (fork, front stand attatchment) is 1914 the rear frame and engine 1921. It has been a WD and was left in France (south of Paris). A foto proves that this is the situation of 1933. May be the rear part has ben damaged during the 1st WW?

I wonder how it works to reduce the distance between the two belt-wheels?

[andertheke]

yes the front (fork, front stand attatchment) is 1914 the rear frame and engine 1921. It has been a WD and was left in France (south of Paris). A foto proves that this is the situation of 1933. May be the rear part has ben damaged during the 1st WW?

I wonder how it works to reduce the distance between the two belt-wheels in order to put on a new endless belt?

[graeme]

Hi Peter
The endless belts are available in 1 inch increments, so you don't need to adjust the rear wheel to fit the belt, just get the correct size of belt.
Now in looking at your picture again, am I correct in seeing that the rear upper stays are welded to the frame below the seat post? If this is the case it will not be possible to fit an endless belt I'm afraid, you obviously need to separate the frame somewhere to get the belt fitted.
Regards, Graeme 

[andertheke]

Hi Graeme,
I wold try to remove the rear wheel and adjust the belt and build in again. At the end I would try to pull it over the little wheel near the gearbox. My only problem is to bring the two "wheels" more near togeather!

[eddie]

Peter,
           You don't need to move the wheel to get the belt on or off - Brammer belts stretch enough to remove them with the wheel in place. To remove a belt, start from the bottom of the rear wheel and pull the belt over the side of the rim, then turn the back wheel until the belt is completely off. Reverse the procedure to refit the belt

  Eddie.

[andertheke]

aaaaaaaaaaaaaaaaah. Perfect!!!
I didn't expect this simple solution.
Thanks very much!

[andertheke]

how do you release the Little bolts? I expected a 1/4 turn, but my tool doessn't grap the round head of the bolt.

[eddie]

Peter,
           Do not try to turn the 'bolts'! They are pins that are rivetted into the links of the belt. If you look at the links, the narrow end has the pin in it, then there is a hole in the middle of the link and another hole at the wide end, and there is a cut between the 2 holes. Now, if you bend the belt in the opposite direction to normal, the pin will go into the cut between the 2 holes, the wide end of the link can then be levered off the pin. When you repeat the process with the next link, the belt will then come apart. Repeating the process again will allow you to remove a link, should you need to shorten the belt - this is the reason there is no need to move either the rear wheel or gearbox in order to adjust the belt.

Eddie

[andertheke]

Thank you very much, this was also very helpful. When you are reading old books about early motorcycling, it sounds extreamly complicate. Nobody ever told that it is/was so easy.

[Ian]

One thing, make sure you do not overtighten the belt as the bearings in the gearbox could suffer excess wear