Dave,
I have copied over the questions form your website and replied point by point, to make it easier for everyone else to follow. Quite a number of questions I must say, and it took a bit of time to put a reply together (during which Roy has also replied), but here it goes.
- Ref: Engine number : YE 6255, Frame number : MF 6983
1) The front brake does almost nothing and the rear brake does almost as little so I will need to find someone who can sort out these servo brakes. The rear brake seems to bite but not until near the end of the travel of the actuating arm. Is there anyone who is known for being able to sort out these servo brakes who you can recommend?
This brake has been written up in the forum, and like the Velocette clutch, a source of endless discussion. In summary it is a single band expanding brake, sometimes of nominal servo action depending on year, model, and condition. There are three adjuster screws inside the band; these need to be adjusted till the band is just shy of the brake drum. Otherwise, as you describe, the band will not contact the drum till you have used up nearly all of the travel of the operating arm. If they apply but do nothing, then the linings are probably contaminated with wheel bearing grease or glazed. Setting these screws can be a bit tedious with a lot of trial and error fitting. Everyone seems to attack/fettle their own, I know of no one specializing in Douglas band brakes. Take heed of the warnings mentioned in the links following if you get the linings renewed.
Link to a topic on the servo band brake in the Reference Section
here, and in the
General Discussion section
here and
here.2) The oil system... is mine a 26 or a 27 type? Is there anything that I need to know about it? How might I test to see if the system is working? The timing chest has two oil pipes coming from it which I'm told indicates that this machine has the later 1927 system. Is this correct? and what about the tube oil that goes directly into the forward facing cylinder?
The oiling system has been written up in the forum, see
here. Operation will also be described in the reprint handbooks you ordered, along with illustrations. In summary (for the system you have currently fitted) oil enters the engine via the oil pump, then back up to the sight glass, then to the non-return valve (further described
here) at the base of the front cylinder. Oil that accumulates in the timing chest is picked up by a second stage of the pump and fed through drilling in the crankshaft to the big ends. Oil that accumulates in the crankcase proper eventually escapes past the rings to the combustion chamber. Supplemental to this, you can add oil by the hand pump, which flows through the sight glass, to the non-return valve and etc. All oil goes through the sight glass, so you always have a visual indication the system is working (besides smoke is emitting from the tailpipe!) You can cut off oil to the mechanical pump by closing the tap. As the hand pump has its own internal connection to the supply of oil in the tank, it remains unaffected.
Your engine number suggests it is early enough to have been fitted with the gear oil pump with single line to the timing chest, but it is obviously now fitted with the later timing chest cover with the plunger pump and two oil lines. I do not think they waited till 1927 to change over to the plunger oil pump with two oil lines, and many gear pumps would have been subsequently changed over to the improved system by the factory or dealers. The factory would provide this service via post on receipt of 25/-, the original timing cover, oil pump, pipes, and tap.
3) I'd quite like to find some foot boards for it and maybe a chain case for the primary (do you know of anyone who may have these parts for sale?). The foot pegs seem very low and would ground out very easily. (The kick start pedal is a little bent). Stop Press : John Caddick is sending me some foot boards in the post.
Yes they do seem very low, it looks as if someone just bunged footrest rubbers on the ends of the rear footboard supports. But the rear support looks to be in the right position for the footboards. How far do you figure you will lean it over?
The primary chain case is a sheet metal cover over the face of the chain and sprocket, rolled over the sides with suitable bumps and recesses. It was open to the back (engine/trans.) There should also be a separate sheet metal strip wrapped around the clutch sprocket to prevent chain lube from being flung off to the front. This had a notch in it to allow the clutch release arm to pass.
4) Armours are sending me a complete exhaust system. The current one looks 'wrong'. The silencer is a bit bashed around and the pipe seems to point downwards. I assume that the pipe should be nickel plated and the silencer should be painted?
Mmm, I hope it fits… The current system does look a bit cobbled-up. The curve of the front pipe looks good, but the rear pipe joins the main run too abruptly. It should sweep into the main pipe as you will see in pictures of other EWs. Also the front pipe just slips inside the rear pipe, where as your’s seems to have some sort of compression fitting or coupling sleeve fitted. The pipes were nickel plated, as was the tailpipe portion of the silencer. The body of the silencer was painted black. On more deluxe models (and the bigger models) the entire silencer was plated, as they are in many restorations.
5) I've fired it up and it sounds beautiful! There is a real readiness to the throttle too. It soon stops though as petrol gushes from the carb and the rear cylinder oils up almost immediately. Maybe I need to drain the crank cases first? There is something 'clanking' but it could be somewhere in the transmission so I need to investigate further.
If the bike has been sitting a long time, draining off the crankcase is not a bad idea. The drain plug is below and to the rear of the timing chest, low down (obviously) in the face wall of the crankcase. However eventually it should burn off the extra oil. Do not drain off the oil from the timing chest as that would just delay the oil supply to the crankshaft while waiting for the level to be restored. There should be a line coming out of the timing chest that is part of an internal standpipe that sets the oil level. Excess is lead over to lubricate the primary chain. Unthread the stand pipe and make sure it is not cut off (it should project about two inches into the timing chest) and that it has not been blocked off. (As yours is, I can see in one of the pictures where someone filled the fitting in with soft-soldered.) The primary chain could be thrashing about, creating the clanking noise. Or it could be the transmission.
6) I have seen a photo of another EW without a primary chain case and with the same top run shield. Was this an optional part?
I assume you mean this one
here. No, it is the incorrect part, patterned on what was fitted to some 2-3/4hp models.
7) The top nut on the steering head... does this part look ok? Should it have a hole in it? I assume that it should be nickel plated?
You are probably talking about the cap that snaps on to the steering stem nut. Yes it should have two slots either side, and it is cast aluminum painted black. Originally all the control cables passed through the slots and down the center of the steering stem to ‘tidy’ the front end. It does put quite tight bends in the cable, hindering smooth operation, so most have reverted to more ‘modern’ cable routing. You can get extra-flexible Bowden wire and in conjunction with Teflon sleeved casing might well work fine (this is what I will try.) The original cable might also have been extra flexible to allow the tight bends, but replacement cables too stiff and/or routing them through the steering stem too much bother.
Does anyone know the origins of this particular Douglas? It came from a dealer who could tell me nothing other than it came from the South of England.
Um, beside that it came from Kingswood, Bristol? Sorry, I could not resist!

No clue.
9) The wheel rims hold beaded edge tyres. 1926 seems to have been changeover year top wired tyres so I think that beaded edge type is probably original? The tyres look like they are real originals so I'll need to change them for safety reasons.
Drop center rims and wired on tyres were an extra option on some 1929 Douglas models, but really did not become standard till 1930. Even at that, the cheap lightweights persisted a few years more with beaded edge to keep the weight and costs down (and to use up old inventory.)
10) Is there anything else about this Douglas that looks 'incorrect' or is there anything else that I should be aware of?
Only in a nit-picking sense. On the whole, it is fairly complete and correct. Far better than the rusty frame I’ve started with. But since you asked for it, besides that mentioned elsewhere:
• No rubber would be fitted to the kick start pedal, and the lever would be nickel plated.
• Originally the lever would be mounted horizontal, which limits the amount of swing. It is believed this was intentional, as the internal stop mechanism, or lack of it, left the end cover vulnerable to damage. Most owners have repositioned the levers higher up, and take care not to over-stroke the kick start.
• The end cover for the transmission (enclosing the kick start mechanism) should be painted black. Only the end-cover so far as I know, not the aluminum plate casting behind that closes off the gearbox. Any comments from the forum?
• Rear stand clip looks like a replacement, and does not leave enough room for the Scotsman transfer between it and the rear number plate.
• The saddle has been slid too far forward.
• Post war push-pull fuel tap on the oil tank.
• Front brake cable adjustment is nearly used up. The brake actuating arm should be at 90 degrees to the cable/rod when the brake is applied. Here it is already well past center. The brake actuating arms have an eight-tooth spline; this looks like it needs to be pulled out and rotated clockwise one spline increment. It also might indicate the linings are completely used up.
• The brake backing plates should be painted black.
• The volute clutch cam return spring does not seem to be doing much when the clutch is relaxed. It should remain under some tension, even when the clutch is engaged and the pressure off the clutch throw-out bearing.
So as I said, nothing earth-shattering. And other than sorting the brakes, all of a cosmetic nature.
11) There is a lug on the frame in between the saddle and the gearbox area. Is this for a carbide mixer?
Yes, or the accumulator carrier, had it been an electric lighting model.
12) Should the gearbox contain grease or oil?
Both. Gearbox lubrication has been written up in the forum
here and
here.. The simple answer- it is something with the viscosity between grease and oil.
13) The carburettor is a 'Brown & Barlow'. Does this look like the correct unit for this Douglas? It does leak a lot at the moment and this will be one of the first parts to come apart for cleaning and examination.
Yes it looks right. It should be a model 123-5, cast in raised numerals on the side of the mixing body opposite the B&B logo.
14) Transfers... I'm aware that a full sized primary chain case would have a transfer on it. What about the head stock or any other part of the EW?
Scotsman in color upholding an engine on the headstock, the ones already on the petrol tank, and a small transfer admonishing riders to use the clutch when changing gears (for the benefit of previous clutchless 2-speed Dougie owners) on the top frame tube just in front of the saddle spring clamp. Also I believe they used an additional Scot upholding an engine in gold on the rear mudguard between number plate and rear stand spring.
The transfers are available from the LDMCC and the VMCC in the UK, except for the clutch notice, which I believe only the VMCC stocks.
15) I have a pile of reproduction literature on its way from Australia at this very moment which may fill in some of my knowledge gaps. I do have the Carrick and Briercliffe/Brockway books and have joined the LDMCC. One of the best sources of information is this website douglasmotorcycles.net . I'm looking for a copy of 'The Best Twin'.
Go for the second edition of “The Best Twin”, it has more pictures in the back and the benefit of updated and corrected text. More info in the Bibliography section
here.Nice plug for the forum, by the way.
16) The clutch does very little (it does not separate) so this will need to come apart. The flywheel looks like it has taken a slight knock at some point. Is there anything that I need to know about it? I'll need a flywheel extractor if anyone has one for sale. (I'm not an engineer so can't make one myself!)
Flywheel clutches have been known to wobble from the Works! They are pretty simple, but there are a lot of loose rollers that may fall out when you dismantle it. The clutch was introduced just a few years before, and went through a lot of early detail changes, which continued right through the EW era. That ought to tell you something… There is not a lot of travel to the clutch, so you need to keep the minimum of slack in the cable. There are cross-sections of the clutch in the manuals you ordered. It looks like yours might be backed right off on the adjustment. Also there is a course adjustment by rotating the ring on the crankcase that the clutch throw-out cam runs against.
Topics on flywheel clutches
here, here, here, and
here. Eventually you may run across this post
here but note this depicts a 1924 clutch and it is a little different than what you will have despite appearing externally to be the same. It has balls instead of rollers and in other respects the EW clutch was greatly simplified (and cheapened.) As time went on they had to make the clutch more and more robust.
17) The manual oil pump can be pulled up and then it goes down slowly. I think that this is expected behavior? The regulator on the sight glass does work too. On my Ariel I usually set this to about ten clicks out. Would this be a good starting point for the Douglas?
Yes it is. The hand pump is spring loaded and feeds oil on the return. The number of ‘clicks’ is arbitrary, and could vary with the viscosity of the oil and ambient temperature, configuration of the needle and seat, how fine the thread for the needle spindle is, the tides, if Jupiter is in the house of the Scorpion, etc. Suitable oils have been discussed on the forum, as well as ‘drips per minute’ or ‘drips per mile’, see oil links under question 12 above. There should be a little smoke visible on acceleration.
Others will probably provide the setting they run with, but for starters the handbook suggests setting the needle valve on the sight glass such that a full stroke of the hand pump lasts 5 to 7 miles at a steady speed of 20-25mph. With the tap open and oil being circulated by the mechanical pump, the drip rate should be the same. Obviously it is safer to start out a little generous on the oil supply and gradually cut it back. The 2-3/4hp machines like a good slug of oil when climbing hills to help seal the rings and provide a slight more compression (and power); the EW should be similar in this respect.
Pictures of other EWs, in the Reference section
here and
here. Note the first appears to have the larger 600cc EW silencer canister fitted, it was slightly longer in body compared to the 350cc.
Enough for now!
-Doug