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General => Douglas Motorcycles - General Discussion => Topic started by: Parsnips on 08 Sep 2021 at 08:27

Title: 250 crankcase breather
Post by: Parsnips on 08 Sep 2021 at 08:27
Can anyone assist me with identifying what is the correct fitting to mate with the holes on the top of the timing gear case in the photo?

(https://www.douglasmotorcycles.net/aa-files/images/parsnips/2021/20200923_170554.jpg)




[embed image. 08Sep21 -Doug, Admin]
Title: Re: 250 crankcase breather
Post by: Doug on 08 Sep 2021 at 12:42
(https://www.douglasmotorcycles.net/aa-files/images/doug/2021/250-breather/250-crankcase-breather.jpg)

(https://www.douglasmotorcycles.net/aa-files/images/doug/2021/250-breather/1935-vent-tube-sketch.jpg)

PDF file of sketch (https://www.douglasmotorcycles.net/aa-files/images/doug/2021/250-breather/1935-vent-tube-sketch.jpg)


(https://www.douglasmotorcycles.net/aa-files/images/doug/2021/250-breather/1935-vent-tube-1.jpg)

(https://www.douglasmotorcycles.net/aa-files/images/doug/2021/250-breather/1935-vent-tube-2.jpg)

(https://www.douglasmotorcycles.net/aa-files/images/doug/2021/250-breather/1935-vent-tube-3.jpg)

-Doug
Title: Re: 250 crankcase breather
Post by: Parsnips on 08 Sep 2021 at 13:11
Many thanks Doug, it shouldn't be too difficult to make up something similar. You have also answered something else that has been puzzling me - how the primary covered is fixed is also shown in your photo.
Thanks again, Mark
Title: Re: 250 crankcase breather
Post by: Tazmantic on 13 Oct 2021 at 18:12
Nice to see another 250 owner, I made one for mine out of some steel square section and some copper pipe.
Title: Re: 250 crankcase breather
Post by: Cliffy73 on 19 Nov 2021 at 19:27
Hi I have a spare 250 breather if you still require one.
Title: Re: 250 crankcase breather
Post by: Parsnips on 23 Nov 2021 at 17:27
Thanks but I managed to make one that does the job, I would be interested if you have any other 250 parts.
Title: Re: 250 crankcase breather
Post by: Cliffy73 on 23 Nov 2021 at 18:56
I also have a 250 which I'm trying to source enough parts to build a spare engine. Finding a good crank is hard work.

(https://www.douglasmotorcycles.net/aa-files/images/cliffy73/2020/1936-Douglas-Aero-250-01-900.jpg)

Image converted to linked file - Dave,26Nov2021
Title: Re: 250 crankcase breather
Post by: EW-Ron on 24 Nov 2021 at 19:43
So remind us, why would you need a 'spare' engine.
That one looks superb enough as is ?

I always think that when you find every example is completely knackered,
they obviously had good use out of it  !
Title: Re: 250 crankcase breather
Post by: Cliffy73 on 24 Nov 2021 at 19:56
It's always nice to have a spare unit as it will be covering a fair few miles. They are not the best unit and are very prone to sieving up due to the thickness of the cylinders . I've looked at making it a larger capacity but it not that easy.