Q. What is a sludge trap and why is it so important?
A. The sludge trap is a tube inside the crank cavity. It is essentially a centrifugal oil filter that protects your connecting rod bearings from solid carbons. Over time the trap fills up creating a blockage of oil flow to the connecting rods causing a seizure. In the picture below you can see the there is a solid build up and anymore "muddy" build up. When a bike sits for 30 years or more the sludge starts to harden, this is especially dangerous. When you run the bike with this you take a solid risk of the carbon loosening up and making its way into the connecting rods. Unfortunately there is only one real way to clean this and that is by splitting the cases and removing the trap, that is really the only safe and effective way to clean it. The upside is now you know your motor has a clean bill of health. As for future care you have two options; running a remote oil filter and changing your oil more often, every 1000 miles is a good start.