Guys
I am at the Point where I am Fitting Caps to Tanks yesterday fitted the Oil tank Cap
No Problem but this day grabbed the Fuel Tank Cap from its Storage Location dusted it off well even you would be dusty after 3 years in the Man cave and noted it does not have a Gasket whereas the Oil tank Cap did and they were both purchased from the the Same Reputable Offshore Supplier which Evokes 3 Questions.

1. Should a Gasket Be Fitted ?

2. if A gasket is fitted is A Breather Hole required ?

3. Is the 3/32" (2.5mm) Split Pin Robust enough to retain these Caps?

Cheers

Ron FTLDU



in 42 days

email (option): Grumpy.moran@gmail.com

Hi Ron.

Yes, a gasket is needed or you will get fuel all over the tank
And even down to your “privates” otherwise, when tank is full.

The breather hole has to be free,
Because if it is blocked and the cap has a good tight sealant action,
You will have a fuel starvation problem,
mainly when on a highway or long straights, and even more when the tank is full,
as then you have laess air space.

The split pin is not really an issue,
And it is there only in order to act as a hinge, and to keep the cap from faling.
When the cap is closed, no stress is applied on it.

The subject was discussed few times:

http://pub37.bravenet.com/forum/static/show.php?usernum=3155626639&frmid=16&msgid=1254640&cmd=show

Good luck,
Noam.

email (option): Noam10@gmail.com

**The cap's vent hole has to be clear,
But at the original cap, has a dished cover from the inside,
Which allows to avoid vacuum, but stops the fuel from gushing out.
A kind of a raw one way valve.

Noam.

email (option): Noam10@gmail.com

Noam
Thanks for confirming this the cap has neither gasket or vent hole so it looks like I will need to make as gasket fit it and drill a vent hole

Cheers
Ron

email (option): Grumpy.moran@gmail.com

Hi Ron,

Strange,
All of the caps I saw so far were with a vent hole.
Now, I searched the web for photos, I found 2 kinds..

email (option): noam10@gmail.com

My WM20 oil tank cap doesn't have a vent hole, maybe it are just the petrol tank caps that have one as they need one.

Henk

email (option): ahum@quicknet.nl

I think the oil tank has a separate breather.

But if the BSA oil tank cap has no breather hole you wouldn't be able to use it on a Norton petrol tank even though its the same size?

Rob

email (option): robmiller11@yahoo.co.uk

Fortunately not.. ...Ian

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

I was reminded of a previous post about overpriced Norton caps from India.

http://www.ebay.co.uk/itm/British-motorcycle-gas-tank-caps-lids-BSA-Triumph-Norton-Matchless-Royal-Enfield-/121091255944?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D6866850531238469815%26pid%3D100011%26prg%3D1005%26rk%3D2%26sd%3D111025826412%26

Unfortunately you can't see from the pictures if they have a breather, but I think its interesting that the box is labelled as a Norton part when in fact its a part not made by Norton and could fit other makes.

Rob

email (option): robmiller11@yahoo.co.uk

Hi Ron
My unrestored fuel and oil caps both have gaskets (look like cork), neither have vent holes and both are labelled ENIHS in an oval and Made in England. The H in the name stamp is a bit unclear could be an A or II. They both look original.
Best wishes to All.
Doug W

email (option): watsond@xnet.co.nz

Brand is ENOTS.
Large wing nut caps should all have vent hole and baffle, Competition only KM24,WM20 and Inter Norton.
BSA WM20 wing nut oil caps are not vented due to vent pipe on oil tank, this size cap also used as fuel cap on post war Goldies and other compy BSAs, but these also have vent pipe on tank.
It must be the non Inter Nortons and possibly other makes which have the vented smaller caps.

email (option): n.gentner@bigpond.com

Yes Neale is correct the brand is ENOTS and the vent hole is probably covered up with the gungy thick black brushed on paint that has been protecting the bike for many years. Doug W

email (option): watsond@xnet.co.nz