OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Briggs Quantum on a Rover Base - Self Propelled

Hi Guys,
My Dad has been on the job picking me up some good mowers from his home area and he came across this self-propelled Rover which I have never worked on before. Best thing is it came with a mint catcher for $10 bucks all up so good find in my book.
After a quick carby clean and air filter replacement the mower actually runs quiet well however I suspect in will need the valves lapped and ground because once the engine warms up you get a light miss through the exhaust � I will check the clearances in the morning but I suspect it will need a valve job which is pretty simple. I am not concerned about this problem.
Now to the self-propelled function � All Dad and I actually did is clean out the area which surrounds the belt which included sticks, dirt and just about anything else you can imagine. The self-propelled now works really well. It�s actually a struggle to keep up with the mower once it is going.
My question surrounds how I properly service the self-propelled function to ensure longevity. I have tried to find other threads but the forum is pretty light on from what I can find.
Before I bring the mower back home I�d like to understand more about the self-propelled function and understand the servicing requirements.
Thanks a lot
Peter