These are very fine motors if they have been looked after. They are heavy compared to similar output 2 strokes but by comparison sip gas, dont stink and are relatively quiet. Aside from oil changes(1 litre/one quart) once a season they require no more maintenance than 2 strokes or more modern 4 strokes. The ignition is generally bulletproof but now new replacement parts are increasingly hard to come by without some effort. If they have good even compression,start with a minimum of hassle(as they should) idle well, push a steady stream thru the telltale,show no signs of water in the engine o or lower unit oil, shift easily and show little blue in the exhaust they are good to go. They are prone to carb related problems (usually plugged jets) if left unused for long periods without draining the carb,however the carb is simple yet refined and as a rule fixable without a lot of hassle. generally these problems can be avoided by adding carb cleaner to the fuel every two or three tanks, draining the carb (easy) before storing and storing in a evenly heated dry area(fine jets are prone to corrosion plugging.One last point is to ensure the green light comes on when running (oil pressure } If no it may just be the bulb or more serious oil pressure failure(game over). Hope this helps
