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Douglas 1913 Model P motorcycle

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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 retention and removal

Started by tck, 15 May 2007 at 12:48

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tck

Hi .I have a 1925 2 1/2 sv douglas (late clutchless 2 speed) and an early 1926 350 EW
I would like to regind the valves,all the books say its easy and can be done by the side of the road
but.
A. what does the valve compressor look like -if I had a picture I could make one
B.The books are very coy about exactly how the valves are retained-cotter-pin-wedge,thread?

Chris

    A valve spring compressor is not necessary for the 2.3/4hp as the springs can be compressed by hand and a pair of long nose pliers used to remove the cotter pin which is simply a parallel pin about 1/8" diameter. To prevent the valve lifting when compressing the spring a small piece of wood about 3/4" cube can be placed behind the valve cap and the cap temporarily replaced. When the pin has been removed the valve cap and piece of wood may be removed when the valve and spring can be removed. If you want to see what Douglas originally provided for compressing the valve spring, you can see it in the parts list for the 2.3/4hp models on the first page of photographs of the accessories. It is made by "Terry" and they can still be found at auto-jumbles.
   For the EW model a compressor is necessary and the cotters for this model are two halves of a parallel cotter held in a recess in the top of the valve stem within a recess in the spring cap. Chris


tck

Quote from: Chris on 15 May 2007 at 17:46
 
   For the EW model a compressor is necessary and the cotters for this model are two halves of a parallel cotter held in a recess in the top of the valve stem within a recess in the spring cap. Chris


Ah so the EW is like my Vincent and the 2 3/4 is real Vintage-what a difference in models yet only one year in production!
Many thanks Chris its often the easy parts for those that know that are left out for those new to a marque

Alan Cun

Hello All     If I can put my ten cents worth on this one      The valve stems , the guides , the followers, the follower rod and nut housings all suffered severe wear on the TS.   A friend of mine came up with valve guides from Z4oo Kawasaki but they are probably too obsolete now. The old ones do drift out.  If your seats are past the stiff attack with a wire brush in the drill this is how he did the seats.     He selected a discarded TS valve that wasnt too worn in the stem and with a cutoff blade in the small angle grinder cut a radius cut in the head of the valve.     Within this cut he then inserted a piece of triangular lathe tip tool with cutting clearance, and then silver soldered it to the seat angle. All that is needed then is to cut the new seat carefully with the aid of a battery operated drill.  Sorry dont know what replacement valve but maybe Datsun 1200.    Short of the Adjustable  followers ,  Maybe you have a mate with 16H Nortons.Got another story coming up on modifying a TS and CW but need to borrow some parts to photograph keep on watching. ( sorry no pics this time  on the cutter couldnt find the one I made. )  regards Al