Oil leak

Timing side cover, the case screw above the first N of the Norton logo on the case. This was ok when I first got the bke but started to leak badly when the engine was warmed up. I tried stopping it first with a fibre washer behind the screw head, then changed the case screws to allen bolts to get them tighter, then tried a copper washer under the bolt head, eventually stopped it with a combination of a copper washer and RTV under the washer.
I'm concerned though that I might be simply masking a problem rather than curing it.
Is this a normal place to leak oil from?
I haven't had the timing case off so don't know what lurks under there, but the manual doesn't seem to show any oilways or galleries in the immediate vicinity, so why should it start to leak there?

Millard

millard said:

Is this a normal place to leak oil from?
Millard

Click to expand...

It's a Commando Old chap, they can leak from anywhere

There are no oil feeds in the vicinity but it is the closest screw to the oil drain from the head and on an 850 is not far from the breather which might mean that oil is drawn in that direction rather than just splash.

If the breather is in order then it's probably just a case of a damaged gasket, assuming no hairline cracks or porosity in the case. The screw enters a blind drilling so normally, if the joint faces are flat and the gasket in good order, it shouldn't matter if the screw thread seals or not.

Once oil starts to be drawn through a bad joint, capillary action seems to do the rest.

Millard,

As 79x100 says, it's unlikely to be anything serious, just a leaky gasket allowing oil to get out of the screw hole, if it had been the screw immediately below the rocker feed banjo then I think I'd be inclined to change the gasket, but if you are happy with it as it is then I wouldn't worry.

cheers guys