BSA A50 PRIMARY OIL LEAK

[blackeyeian]

HI ALL
I SEEM TO HAVE A PRETTY BIG OIL LEAK FROM THE DRAIN BOLT ON THE PRIMARY.  WHEN I TOOK THE PRIMARY OFF THE ONLY BOLT THAT HAD A WASHER WAS THE DRAIN BOLT WHERE THE LEAK WAS. IS THIS NORMAL OR WOULD IT CONTRIBUTE TO THE HEAVY LEAK?  ALSO, WHAT DOES EVERYONE THINK ABOUT SILICON SEALANT ON BOTH SIDES OF THE GASKET WHEN REFITTING?  REGARDS

[Bess]

Hi,
    Not sure what you mean regarding the drain down, perhaps some images would help.

On the primary, my experience with silicone sealant is, no gasket but a light smear on the joint surface on one side (say engine side) smear oil on joint surface of the cover and assemble
. It will come apart in the future without driving a wedge in the joint edge damaging the surfaces. Blue Hylomar would be better if you want the additional.

However the professional option is to cut your own using

https://www.gore.com/products/gore-gr-sheet-gasketing

Best wishes...

[bikerbob]

The drain bolt should have a fibre washer fitted, oil does tend to leak along the threads and without a fibre washer can leak. As regards gaskets I make my own from gasket paper which can be bought quite cheaply off ebay various thicknesses I use 0.40mm for most gaskets but thicker for the rocker cover gaskets, and use a thin smear of grease on both sides of the gasket, I have been doing this on both my A7 and A65 for a while now and have no oil leaks from any gasket that I have fitted.

[blackeyeian]

THANK YOU FOR YOUR REPLIES
MY DRAIN BOLT HAS A METAL WASHER - NOT A FIBRE ONE - SEE PIC -
WHERE CAN I GET THE CORRECT FIBRE WASHER OR DO I HAVE TO MAKE ONE
REGARDS
IAN

[JulianS]

Aluminium crush washers were sometimes used here.

You should be able to find fibre washers the appropriate size on ebay, a few pounds should buy enough to last for years.

[blackeyeian]

Thank you all for your help
Regards
Ian