motor fails to shift into neut. and rev. dropped lower unit, then tried shifting with throttle box. everything is free here. motor is a 79' 80hpr merc. i checked the nylon pieces that assemble around the shift shaft. they seem ok. i can turn the main shaft, the prop turns in fwd, when i turn the shift shaft , i can't find a neutral position and also can't find a spot where the unit will go into reverse. not sure what iam doing wrong. i suspect something let loose or seized up below the shift shaft. i'm hoping someone might have a logical explanation of how the shift linkage works and how to realign the parts to get it to work again. motor is too old to dump tons of money into it so i fix what i can by myself. please help! thanks chuck