Jstep
Seaman Apprentice
- Joined
- Jun 15, 2009
- Messages
- 43
I have a 1969 Mercruiser 160 that I am trying to drain before I put it into storage. Figure 5 on page 1A-8 of the service manual shows 3 drains; two marked "Sea Water" and one marked "Fresh Water". I was able to easily find the "Fresh Water" drain on the block, which was more like a thumb-turn valve. I opened it, and probably about a gallon came out from here.
I am having trouble locating the "Sea Water" drains on the manifold. First off, my manifold does not look like the one pictured. The four plugs on the side of the manifold with the square hole are actually on the bottom of my manifold, and I do not have a drain plug on the elbow where it is pictured in Figure 5. My manifold actually looks exactly like the Merc 120 manifold in Figure 6.
I removed what I thought was a drain plug from the bottom of the manifold, from the location pictured in Figure 6, but no water came out. The hole also seems quite plugged up, and I was not able to unplug it by probing with a screwdriver. Here is the "plug" I removed from the bottom of the manifold:
Am I missing a drain plug somewhere? Did I remove the right one from the manifold? Did part of it break off inside, or do I just need to be more aggressive with the screwdriver? What about using a drill to poke through it?

I am having trouble locating the "Sea Water" drains on the manifold. First off, my manifold does not look like the one pictured. The four plugs on the side of the manifold with the square hole are actually on the bottom of my manifold, and I do not have a drain plug on the elbow where it is pictured in Figure 5. My manifold actually looks exactly like the Merc 120 manifold in Figure 6.

I removed what I thought was a drain plug from the bottom of the manifold, from the location pictured in Figure 6, but no water came out. The hole also seems quite plugged up, and I was not able to unplug it by probing with a screwdriver. Here is the "plug" I removed from the bottom of the manifold:


Am I missing a drain plug somewhere? Did I remove the right one from the manifold? Did part of it break off inside, or do I just need to be more aggressive with the screwdriver? What about using a drill to poke through it?