DJ_Allatoona
Petty Officer 2nd Class
- Joined
- Feb 24, 2008
- Messages
- 187
1986 Mercury 75HP. Serial #0A984714. After eleven years of mostly rock-solid service, something very serious-sounding happened the other day. I launched and idled fine, then crept out of my creek at no-wake speed for about 15 minutes.
When I throttled up out of the hole, I knew immediately something was off. RPMs and power were normal, but there was a metallic rattle sound and high-speed knocking. Throttled back to about 25% and it stopped. OK, it's a cold morning, and this motor sometimes does random things and makes random noises that come and go. I didn't turn around.
Gave it a few minutes, then throttled up again to about 50%. The sound was back louder, accompanied by a fast vibration, shaking, grinding, and a funny 'slipping' feel in the propulsion. Definitely something was spinning off-center and knocking metal. Before I could get back down to idle, a solid THUNK and it shut off.
Pondered life for a few minutes, tried the key again and got a powered click from the starter, but there was resistance and nothing turning. Seized. Electrics all worked so I tilted up, paddled toward home until a good Samaritan towed me in.
My thought is one or both of the drive shaft bearings failed, because of the off-center spinning feel and grinding sound. I won't be able to drop the lower unit for another few days, but best-case scenario is I can fix this as a fall project.
Worst-case, I never bought JUST a motor before, and I cannot believe the prices out there, even for older motors that need work. I see a lot of fully-rigged boats for cheaper than just a motor. Amazing.
Anybody got thoughts on my dead motor? And where would you start looking for a used motor if you were me? I'm in Georgia.
When I throttled up out of the hole, I knew immediately something was off. RPMs and power were normal, but there was a metallic rattle sound and high-speed knocking. Throttled back to about 25% and it stopped. OK, it's a cold morning, and this motor sometimes does random things and makes random noises that come and go. I didn't turn around.
Gave it a few minutes, then throttled up again to about 50%. The sound was back louder, accompanied by a fast vibration, shaking, grinding, and a funny 'slipping' feel in the propulsion. Definitely something was spinning off-center and knocking metal. Before I could get back down to idle, a solid THUNK and it shut off.
Pondered life for a few minutes, tried the key again and got a powered click from the starter, but there was resistance and nothing turning. Seized. Electrics all worked so I tilted up, paddled toward home until a good Samaritan towed me in.
My thought is one or both of the drive shaft bearings failed, because of the off-center spinning feel and grinding sound. I won't be able to drop the lower unit for another few days, but best-case scenario is I can fix this as a fall project.
Worst-case, I never bought JUST a motor before, and I cannot believe the prices out there, even for older motors that need work. I see a lot of fully-rigged boats for cheaper than just a motor. Amazing.
Anybody got thoughts on my dead motor? And where would you start looking for a used motor if you were me? I'm in Georgia.
