1986 Mercury, Possible lower unit damage

[111torrance111]

I recently purchased a used boat (1984 Invader) with a 1984-86 Mercury in-line 6 cylinder 90 HP motor. I took it out for the first time and think something happen to the lower unit, the boat loss speed and I just made it back to the doc. The guys at the doc said I ble the lower unit, how can I verify if the lower unit has failed.<br /><br />Heres what I've checked so far.<br /><br />1. With the motor in forward gear I can spin the prop and I hear a clicking sound and the motor doesn't spin.<br />2. With the motor in reverse it seems to spin the motor and works.<br /><br />Jerry

 

[studlymandingo]

Re: 1986 Mercury, Possible lower unit damage

Have you checked to see if the prop spun the hub? Sounds like a more likely scenario. Did you hit anything?<br /><br />It would be a good idea to change the lower unit fluid. If it appears milky or has a lot of shavings in it then you need to check the LU further, I would check the prop hub first, it is designed to fail before the lower unit is damaged.

 

[111torrance111]

Re: 1986 Mercury, Possible lower unit damage

Studly,<br /><br />Thanks for the help.<br /><br />If the prop spins the motor in reverse could it still be a spun prop? I empty the lower unit fluids and didn't see any milky oil, but I saw a few small metal shaving on the magnetic drain plug. The shaving didn't amount to much more then enough to cover the plug.When I drained the fluids I couldn't see any other sign of metal.<br /><br />What is the proper way to check it?<br /><br />Jerry