What is the correct shape plug that enables access to the Mag Pinion? Does it have a large wide slot for a flathead type screwdriver? Or is it similar to a Hex type bolt.

Thanks for your comments.

email (option): unpob@yahoo.com

Hi Henri.. It is the virtually same as the brass plug that fits in the primary chaincase..in fact those do fit. Originally though, the timing cover plugs were made of aluminium...Ian

email (option): ian@wright52.plus.com

Thanks Ian, that is what I thought initially but then came up on this one. Someone punched through the slot (easy fix) to remove the corroded plug. It is now easy to remove

email (option): unpob@yahoo.com

Hi Henri..I don't know where that came from..they always have the hexagon in the middle..Unless the hexagon was knackered and someone filed it of and cut a slot instead...Ian

email (option): ian@wright52.plus.com

That looks like a chaincase plug from a Norton or Triumph or any other Brit bike. Afterall, how may flavors can ya have!

Thanks fore the tip on originality. Ian, you amaze me.

email (option): britool51@hotmail.com

It is probably a earlier plug, also used on Slopers and vertical singles with the magdyno to the front.

My 1939 engine has a steel plug which is also a bit larger than the aluminium ones, another strange part to me is the oilpump cover, this is a machined one instead of the usual formed one. Can anyone confirm these are correct for a military '39?, Regards, Michiel

email (option): m.wijbenga@hotmail.com

Hi Michiel...These things amaze me..something 'new' seems to turn up regularly! I have never seen these two variants before either..Hopefully someone can shed some light on their origins...Ian

email (option): ian@wright52.plus.com

Here's one of them there plugs Henri. Ron

email (option): ronpier@talk21.com

The alloy plug sith the screw slot that has broke through looks like the primary chaincase inspection plug on my 37 HM21. I thought it was the wrong type but having looked at several photos of 1930s BSAs shows it to be correct.Dave.

Thanks Ron, Dave,

I have that plug as well Ron in Alum.

HM21...will have to look it up. Fits fine.

Henri

email (option): unpob@yahoo.com

Henri,

As mentioned in earlier posts it is in fact a mid thirties cap. It has a very awkward screw type slot which no normal tool will fit. So if you find one they are almost always knackered.

Regards,
Leon

email (option): leonhop3@planet.nl

Actually had a socket equipped with this wide flat head screwdriver that I can't remember where I put it, would have posted a photo otherwise.

email (option): unpob@yahoo.com

Any further comment on the parts in the pictures posted by Michiel?...Ian

email (option): ian@wright52.plus.com

I think you need a tool like this one (home made) for the rockerbox caps on Triumphs:

email (option): viaconsu # planet dot nl

Got this gismo:

email (option): unpob@yahoo.com

Ian Wright

Any further comment on the parts in the pictures posted by Michiel?...Ian

email (option): m.wijbenga@hotmail.com

Hi Michiel..They do all look professiomally made..it would have taken some trouble just to identify and machine the thread for the timing cover plug and the sump plate has been carefully machined...in fact it is actually an improvement on the original pattern which wasn't really strong enough...
I think the involvement of the German workshops is an entirely plausible theory...Ian

email (option): ian@wright52.plus.com

Just measured the thread of the plug and it looks to be metric (M48x1.5)......That makes the change German involvement in these parts quite bigger, I would say. But still can't think why they bothered to make these, maybe they frequently lost the aluminium plugs and damaged the oilpump covers ??

Also a picture of the magneto adapter, it has the four half rounds which fit in the crankcase and four holes that match with screws in a Bosch magdyno... Michiel

email (option): m.wijbenga@hotmail.com