Author Topic: I bought Douglas in Japan. Please tell me about maintenance.  (Read 320 times)

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Offline yoshimasa negishi

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Nice to meet you.
My name is Yoshimasa Negishi.
I live in Japan.

I am a beginner for three years since I started riding motorcycles.
I bought Douglas model L - 3 350cc in Japan in October.
I have little experience with vintage motorcycle and Douglas.

The bike is running.
I think that the condition of the engine is good, but there are many white smoke
I plan to overhaul the cylinder.
The tire has reached the usage limit.
You need to replace the tire or rebuild the rim.

There is something I want to know about Douglas maintenance.

I think that it is necessary to replace the 25x3 tire with its limit of use.
Is a tire of 25 x 3 Beatted Edge available?

How many liters of oil is appropriate for oil sump?

Do you have oil or grease in the gearbox?
What is the proper amount of oil?

Where can I buy a flywheel extractor?

What kind of tools do I need to be aware of when removing the crankcase?

People riding Douglas in Japan are rare in Japan.
I am dependent on your abundant knowledge!

Online Eric S

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Hello Yoshima and welcome on board.
I am not the best specialist but I think I can reply to some questions.

On my 1937 Aero the grease in the gear box is a phyloxtropic grease. Solid grease that becomes more liquid with heat.
It can be home made mixing oil and grease but I bought it locally off the shelf from a french company.

On the Aero I don't need a flywheel extractor as the nut is a selfextractor. You just unscrew the bolt and it takes off the flywheel.

Others will reply more in depth.

Offline yoshimasa negishi

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Eric Mr. Hello
Thank you for your answer!

Explanation about grease and flywheel extractor, it is very helpful.

The motorcycle runs again after the repair of the kickstart gear is over.

Thank you very much!

Offline Bert

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Konichiwa Yoshi
On my 1930 T6 with the same oil tank bolted to the engine, I fill it to the bottom of the threads of the filler cap. 


Offline yoshimasa negishi

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Thanks for the reply!

I found a guide to add oil.


Offline douglas1947

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Hello Yoshimasa,

your Douglas looks quite good!

I wonder it has beaded edge tyres, but I think it was possible to get the bike still with this tyres in 1930 (also with acethylene light or lever throttle).
At the moment I restore a 1930 L3 by myself.
It is possible to get a maintance book for the model from London Douglas Motorcyle club (membership?).

Are your shure your piston are worn (because your engine is smoking white)?
May be you should do a test with fresh oil (Monograde W50), if the bike has not run for long time.
For gearbox I would use something like a "Penrite", not a mixture of grease + oil using in the past.
Would you please let me know your Engine Number / Gearbox Number?


Offline Doug

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Beaded edge tyres were standard catalog specification on the lightweight models through 1932. Judging by the catalog illustrations the lightweight models kept the beaded edge tyres into 1935, but they are by then only described as "Best British Make" so it is a little vague on the specification. The heavyweight models started getting well base rims in 1930.

Some of the lightweights intended for the colonial markets had the well based rims in 1930 too. For example the 1930 L3 is specified with 25 x 3" tyres (a beaded edge size), but the slightly heavier H3 intended for export had "26 x 3 wired on tyres" for well base rims.