Douglas - For Sale Items

Douglas 1913 Model P motorcycle

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Douglas 1915 3 Spd-Gearbox and Clutch

Recent Posts

Recent posts

#81
General Douglas Discussion / Re: 1913 douglas big end
Last post by Adam55 - 23 Oct 2025 at 22:51
Thanks Eddie,

The assembled big ends are all done and look great, thanks again for all your help.

Just need to crack on and get it all back together now!

Regards, Adam 
#82
General Douglas Discussion / Re: 1913 douglas big end
Last post by eddie - 23 Oct 2025 at 09:31
I have refrained from giving any further instructions on refurbishing big ends on 2¾'s because there are likely to be too many deviations from standard on machines that are 110 years old! Each engine is likely to be different in crankpin diameter and bigend eye diameter, so shell sizes will need adjusting to suit. Also, recently there seems to have been a spate of big end bolt failures, without a common cause being identified - I suspect (and this is only my personal opinion) that it may be down to modern production methods on the repro bolts (I have reservations regarding certain CNC produced components). Bearing in mind that anything in these old bikes could be seriously worn, I prefer to open out the big end bolt threads from 17/64" x 25 tpi to M7 x 1mm, then replace the original bolts with good quality M7 x 1mm socket cap screws (GKN or Unbrako - don't mess about with cheap Chinese bolts!) - then retain the locknuts with Loctite. Another item which will vary in thickness is the big end keep plates (which also need to be in good condition in order to keep the individual shells pinched up into their respective halves of the con-rod). A lot of these details may seem trivial, but if a rod does let go - it does a lot of damage, so these jobs should only be entrusted to a reliable engineer - it's not something that can be easily taught via e-mail. Now a final piece of advice - these engines are old, and rely on splash feed lubrication - dont try to build them to modern tolerances - the big ends need to be slack enough to allow the oil to get into the bearings - if a rod wont fall under it's own weight, the big end is too tight!

  Regards,
                Eddie.
#83
Hi All
I have a 1925 Cw 350 and require the whole clutch assembly
front brake assembly and front guard
Any help greatly apreciated

#84
General Douglas Discussion / Re: 1913 douglas big end
Last post by Adam55 - 22 Oct 2025 at 19:00
Thank you jonathan, much appreciated.
#85
General Douglas Discussion / Re: MK4 chain adjuster
Last post by Ken J - 20 Oct 2025 at 11:56
Many thanks!
#86
General Douglas Discussion / Re: MK4 chain adjuster
Last post by richson - 20 Oct 2025 at 11:30
Hi Ken,

I used TRIUMPH ADJUSTER,CHAIN 37-2089 available on ebay. These have an offset like the original parts but are more robust.

Cheers, Neil
#87
I am looking for a fuel tank in good condition to suit a 1950 MK 4, should anyone have a spare tank they wish to sell I would greatly appreciate it.

Dave.
#88
Hello Adam, the outer dimension will be entirely dependent on the size of the conrod after cleaning up ( if it needs it )
Eddie did suggest in one of his posts that soldering the shells to the conrod before final finishing was a good way to keep it all tight.
Regards Jonathan
#89
General Douglas Discussion / 1913 douglas big end
Last post by Adam55 - 18 Oct 2025 at 14:48
Would anyone be willing to help with some technical details that a friend needs in order to machine me new bronze big ends for my 1913 douglas?

I think he just requires the outer dimensions.

Any help would be greatly appreciated.

Regards,

Adam
#90
General Douglas Discussion / Re: MkV Oil pump and filter
Last post by eddie - 18 Oct 2025 at 09:12
Paul, 
       There is nowhere in a Douglas oil pump for any foreign matter to collect. With the triangular cover plate removed from the bottom of the pump, you can see into the main chamber and the ports - a visual inspection is all that is needed. At this point, I would leave 'well enough alone' - other than just removing the 2 vanes and spring to check for any wear.

  Regards,
                Eddie.