Thanks for all the advice, guys. I had a closer look at the front of the motor and I suspect the problem may be the timing chain cover after all. It looks like someone has tried to seal it with red sealant of some kind without much success. I will tackle this area first to see if that cures my problem.Can anyone recommend a good sealant?
I was using as much as a quart of my precious Amsoil a day, just now I'm using regular oil (Maxlife 10/40W) which does not leak out as much. I changed the rocker cover gasket last week as the old one was hard and this seemed to help a little.
It would be great if this is the problem after all as I can't have the Merc off the road for long as it's my only transport at the moment on a 200 mile round trip daily commute to Atlanta,GA!
I will keep you all posted. Thanks again for the advice.
Colin