1992 200 hp. yamaha.came in last nite and went to back into slip. when trying to shift into reverse, motor stayed in forward and now will not shift out of gear.shift cable moved shift shaft, but no results. i removed shift cable and shifted by hand. shift shaft moved ,but still stuck in forward. any possible answers? i have read that the shaft or connector rots out. does the powerhead have to be pulled to fix this? thanks