G103 gearbox oil filler cap

[craig]

Working on a 47 Rapide, i need to know the official location for a breather hole in my new G103 "oil gear box" cap. The new cap does not have a vent hole! picture of an original cap would be best
http://www.voc.uk.com/images/vocsc/G103c.jpg

 

[Dinny]

Mines original, the hole is in the center of the flat above the O in oil.. Hope that helps

Mark

 

[passenger0_0]

My 'original' one has two holes on the side only but its a very early old dunga.

 

[ogrilp400]

G'day Craig,
From a practical view, screw the cap on and mark the knob bump facing in closest to the cylinder fins. Unscrew the cap and drill a 1/16" hole under the knob upward at an angle. If you really must go for the absolute original look then choose the flat facing in towards the cylinder fins and slightly rearwards. This is to reduce the risk of water entering when your washing or riding in the rain.

 

[Viny4]

The first twins didn't have breather hole and were of the knurled type, but, with GEAR BOX OIL stamped on the top. Not, (GEARBOX OIL DIPSTICK) The dipstick didn't have a flat on its side.

 

[craig]

Can you be more defining with this information please?
I dont find a note in the "production changes" as to when the fluted early gearbox filler cap was replaced with the more common knurled gearbox oil cap, nor when the "vented dipstick" was introduced.
thank you for any help on this
Craig

The first twins didn't have breather hole and were of the knurled type, but, with GEAR BOX OIL stamped on the top. Not, (GEARBOX OIL DIPSTICK) The dipstick didn't have a flat on its side.

 

[Big Sid]

The gearbox oil filler cap , the early B pattern has a single small hole in one side flute as shown in a photo on this page , two are seen there but someone added the second drilling . The later knurled C cap also has a single hole in its side . I always open the hole to the next size drill bit , helps vent off pressure and moisture , my opinion anyway . I also enlarge the vent holes one size in both tank filler caps , going right through the bottom plate. Sid .

 

[Viny4]

Craig, This bit of vrivia is't that well known. A person would know about the knurled cap on the first production Twins if they had worked on them. When they changed I don't know. Number 34 had one, my Daughter has on on her B that I found at a Swap Meet. I have seen maybe 10 Dipsticks without a flat, hence, no breather hole and posible knurled caps. Many changes were made in eary production that weren't recorded. Number 34 even had a different main shaft in the gearbox. It's an adaptation from the first wet clutches.I showed it to PEI, he had forgotten all about the change.

 

[Big Sid]

Sid here . My own B Rapide , number 275 , was a beautiful machine and was equipped as described . Of course I set it up in Shadow tune as is my nature . Great road bike benefitting from several other small mods .