Re: Tohatsu M90 clunking noise
Here's a guess....The clutch dog facing and the forward gear dog facing are probably worn down from "gently easing the shifter lever in and out of gear". There is a tendency to gently shift in the mistaken idea that you are being kind to the engine. In reality you want to snap it in and out of gear to avoid wear on the dogs. Both the clutch and gear have metal "dogs" on them that lock into place when you shift. Those dogs become worn over time and instead of having sharp edges that lock, become rounded and allow themselves to slip around causing a horrible chattering sound. You can pull the bottom gear oil screw and see if any metal fragments come out with the first drop of oil. If that's the case, figure a seal kit, water pump kit, clutch, forward gear and reverse gear.
