Next time you set your mesh, try a piece of notebook paper folded over. I take a torn off section about three quarters of an inch wide and fold it in half. Then I put between second gear and the second gear pinion on my MT2. Then I adjust mesh so that the gears are tight with the paper in there and tighten down one screw. I then take a corner of the paper and tear off an inch and a half square section and take the precut corner and use it to check the angle of the gear. I do this by placing one cut edge against the clutch bell and the other cut edge against the teeth on the spur. I have run about half a gallon doing this every time I touch the spur gears and they aren't even showing any real signs of wear. This is after destroying two spurs in a month. Let me know if you don't understand any of this.