one thing I left out. If you're getting a LOT of sludge, try using a bit less castor. Maybe a 4.5 or 5 to 1 mix. Also if you can find a source for some synthetic lube it might make things a lot better. Whatever you do, do all your testing on the same engine. If you burn up one engine it's a lot less expense than if you do the same to several.

papermache