Oil and Noisy engines

[daffyduck]

Just swapped the 1100S for a 'P' plate 1100GS. All seems okay except for a couple of minor niggles. Oil is being sprayed back onto the top of my left boot whilst riding, and today I started it from cold and the left pot seems to be making some very odd mechanical noises to begin with.
The oil is very minimal and could be coming from the top up plug on the left cylinder, but could be originating from under the cylinder head before landing on my boot. You can see traces of fresh oil on the rear of the cylinfder coming away from the filler plug to underneath where it then hits the boot. If it is not due to the filler cap O-rings, which appear to have been recently done by the previous owner, what else could it be?
Met seller halfway at Andover, so engine was warmed up by the time I arrived, yet appears to ride and run quite well. Does not have the same amount of power in comparison to my old 1100S. Was told that there was a 18bhp difference between the two. Any thoughts on this anyone?

 

[MikeO]

I'd give it a bloody good clean, leaving no trace of oil, then ride it for a mile or so and carefully look to see where the oil is leaking from.

My guess is that the O-rings on the filler cap should be the focus of your attention (even if they have been replaced recently), but have a look in the spark plug 'tunnel' - there's a rubber gasket at the bottom which is quite easy to misalign when re-fitting the rocker cover (although I'd expect this to produce a significant amount of oil).

Mike

 

[turbine_2]

I've a similar problem on my 1150 but I can tell that it's the oil filler cap, even though looking at the sealing ring it appears fine. Worth keeping an eye on all the same.