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Douglas 1915 3 Spd-Gearbox and Clutch

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Lat Fuller

2025-07-20, 02:39:50
I am pretty desperate for a rear cylinder for my veteran Douglas 1917 2 3/4hp "W" model.   I there is anyone who may have one of these that can be re-sleeved or know where I may find one I would be very pleased for the help.  I have a number of engine parts that I can exchange such as matching crankcases, conrods, crankshaft, flywheel etc. Any help appreciated.

Lat Fuller

2025-06-04, 05:57:00
Does anyone have the specifications for the oil inlet valve spring for early 2 3/4 engines - Part number 424.   I have tried to order one from the club spares but apparently Jeff Swan is indisposed at the moment.

skapoor

2025-05-19, 09:23:12
I am looking for a carburettor for veteran Douglas motorcycle engine-13651. Could you please help me with this?

Drawings for non-return oil valve, Models CO, 600EW, F28, 350EW

Started by Doug, 10 Jun 2007 at 04:08

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Doug

Here are the drawings for the non-return oil valve as screwed into the front cylinder on certain models. Two versions are shown, which except for the lower housing, share identical parts. One uses a 7/16-20 thread, and is as used on the OC, 600EW, F28, and probably other Douglas big twins of the era. The 350 EW needed a special lower housing to clear the adjacent cylinder hold down nut, and smaller, shorter thread to cope with the thinner cylinder wall found on the 350cc barrels. Apparently this is the same as used on the 2-3/4hp models.

Below each is a link to a PDF version (Requires Adobe Acrobat) that you may find easier to print.


Downloadable PDF file


Downloadable PDF file

-Doug

02Jul10  Fix typo, add reference to 2-3/4hp models. -Doug

Petethesign


Neilj

Thanks looks complicated going to have to find a good machine shop