wild.coast
Cadet
- Joined
- Sep 17, 2022
- Messages
- 20
Doing a 100hr service on a new to me Yamaha F50 outboard. I noticed that the inside of the water pump housing (which is plastic) looked like it had melted a little bit! 
Outboards and boat engines are new to me, so curious about others' opinions.
This is how the inside of the housing is supposed to look like:
Notice the little 'wings' facing inwards towards the drive shaft hole.
Now this is how my housing looks like with the metal insert cartridge removed:
Not sure if you can tell from the photos, but looks like those wings melted and then the molten plastic was flattened and pressed in by the metal insert cartridge. You can see the plastic folded inwards a bit on the edges. Sure looks like heat damage to me, but I'm not sure if that's just normal wear or a sign that the engine had a major incident??
The other thing that makes me think so is the state of the thermostat rubber seal:
If it is indeed an overheat incident, I'm wondering if there is anything else I should be checking/replacing/doing to ensure this engine runs reliably going forward?
I currently have it hooked up to a Rydlyme acid flush for a few hours (circulating through engine using a sump pump) to flush out any potential deposits in the water channels.
Outboards and boat engines are new to me, so curious about others' opinions.
This is how the inside of the housing is supposed to look like:
Notice the little 'wings' facing inwards towards the drive shaft hole.
Now this is how my housing looks like with the metal insert cartridge removed:
Not sure if you can tell from the photos, but looks like those wings melted and then the molten plastic was flattened and pressed in by the metal insert cartridge. You can see the plastic folded inwards a bit on the edges. Sure looks like heat damage to me, but I'm not sure if that's just normal wear or a sign that the engine had a major incident??
The other thing that makes me think so is the state of the thermostat rubber seal:
If it is indeed an overheat incident, I'm wondering if there is anything else I should be checking/replacing/doing to ensure this engine runs reliably going forward?
I currently have it hooked up to a Rydlyme acid flush for a few hours (circulating through engine using a sump pump) to flush out any potential deposits in the water channels.
