Hi Jarrad and grumpy, I have found over the many years of operation of my Scotty, a good quality grease is the way to go with the sprockets and chains....rather than oil...In fact all mine are original and have never been replaced. I will however have to replace the small engine sprocket some time in the future, as it is showing signs of wear...but it has done its job for 30 odd years....
The design of the chain case cover prevents dirt and crud getting in there and with regular maintenance should not pose a problem.
