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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?

Valve clearances, Hot or cold?

Started by Evanc, 24 Dec 2013 at 12:11

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Evanc

Hi guys out there in Douglas land. I have just purchased what I believe is a mark 3 that has a Mk5 frame, not sure why it was swapped. I am interested in setting the tappets but am unsure wether they are set hot or cold. It has 6 thou on a plate on the crankcase. Any advice is appreciated, thanks, Evan from Oz
PS hope you all have a merry Christmas, stay safe

eddie

Evan,
          Most Mark series engines had 'Tappet clearance .005' stamped on the top of the crankcase. If yours has a plate with 6 thou clearance stamped on it, then perhaps the engine has been rebuilt with special cams - in which case, it's anyone's guess as to whether that is measured hot or cold. Also, Mark series engines have steel pushrods, so the clearance hardly changes with temperature - unlike the Plus series and Dragonfly with their alloy pushrods.

   Regards,
                 Eddie.