There is another option to try that may give you some information before you attempt to separate the engine
from the gear
. If you take the oil
cap of the sail drive, the shaft in the center (item 23 in the 2nd picture) is the drive shaft that actually turns the propeller
. You can grip the 1/8" that protrudes past the retaining ring with a pair of vise grips (tight enough to hold but not tight enough to dig into the metal) and use the vise grips to turn the shaft, as shown in the first photo
. With the drive engaged, if the input shaft (item 7 in the 2nd picture) splines are good, you should only be able to rotate the shaft in one direction. Shifting to the other direction should only allow you to rotate the shaft in the opposite direction. This is a viable test if the cone clutch
is working properly; if the box is in gear
you're actually trying to turn the engine
over by turning the shaft with the vise grips . If you can rotate the shaft in either direction with the gearbox
in forward or reverse, there is no connection between the engine and the transmission
, and that is your problem.
From your description, the issue lies with either the input shaft splines, the drive plate splines, the lower splines on the intermediate shift shaft (item 23), the splines in the coupler (item 29) or the upper splines in the lower unit drive shaft (item 4). My first guess would be the coupler, because you saw the shaft turning when you ran the gear without the cap, but there could be some residual contact between the splines on the drive plate and input shaft that would spin the gears and make grinding noises but not engage the propeller
Can you tell anything from where the sound appears to be coming from? Is the grinding coming from around the flywheel or does it seem to be coming from lower down?
The crack in the shift mechanism might indicate that someone made a high rpm
shift at some point, and the damage is just now catching up with you.