Jones,
Does it jump out of second gear with "vigor". Sometimes the clutch gear, or more commonly known as the input shaft if worn out. I had this happen and couldn't see the malfunction, but a replacement cured it. Be sure to put a new pilot bearing in the crank when you re-do the motor. The detents in the tower for
the shift collars aren't suppose to keep the
gears engaged they just position them where they are suppose to be. Like fatweed said, the collars can be bad and cause problems too.
Stuart.
