Mercruiser 5.7 Alpha 1 gen 1 external oil reservoir

[Nate_lynch]

Hey everyone, this is my first post here. I did a search but haven't been able to find much info on this specific external oil reservoir system.

I have an old (1989) Thundercraft with a 5.7 Mercruiser Alpha 1 gen 1 on it. This drive has an external oil reservoir which appears to connect to the vent plug on the drive. When I bought the boat the oil line had been disconnected and zip tied to the swim platform. Here is a link to the system I have. http://www.mercstuff.com/reservoir.htm

My question is...why would someone have disconnected this system and is it worth it to reconnect it? I'm assuming that it was disconnected due to an issue with the system. Is there a good reason to have these external systems? ie) is it a good backup in case of seal failure?

Thanks!

 

[greno]

Welcome to the forum!
I would bet that something is wrong with the external reservoir system. Maybe line and fitting are leaking. You cannot just buy the line for these you have to buy the whole system again. It won't hurt to hook it up and see what's wrong with it. Make sure that oil will flow through that line then connect it, put some oil in the bottle and watch it for a while.

 

[Nate_lynch]

Awesome thanks! What's the purpose of these systems? Are they just a backup? This is the first stern drive I've had that has one.

 

[greno]

They keep oil flowing to the upper gears should a seal failure occur while running. Only good if you check the bottle level before every voyage. Newer ones have a sensor that will sound an alarm.

 

[Bt Doctur]

that line should have passed thru the transom and inside the boat should be the res bottle. Tied to the platform it better have a plug in it

 

[tpenfield]

+1 on the transom location for the tubing. Sounds like someone red-necked the oil system. the reservoir is to keep the outdrive full of oil, as it may loose a bit here and there. Normally, you would not need to re-fill it . . . but if you do, then you know something is wrong.