Exhaust water leak?

[sagablu]

Hey All,

Ok, so I am new to boating and a new owner of my first boat, a Pearson 10M. I understand gas engines well enough as I have owned and fixed my own motorcycles for the last 30 years, but know little about Marine Diesels . Please correct my terminology, I need to learn and communicate properly. The Engine is a Yanmar

It looks like I will be taking the boat out for the first time tomorrow so I started the engine to see if all is Ok. Other than the cable to the kill lever(?) being a bit out of adjustment all was ok expect for one problem. Yes, not being able to kill the engine was a bit of a situation but I figured it out fast enough. I am not a moron unless you question my girlfriend.

There is a plastic tank behind the engine with two large ( about 4") hoses attached to it, I assume this is the water muffler? At the bottom of this tank is a small plastic drain that leak about 2 drips a second while the engine is running. I cannot hand turn the drain to tighten. The leaking fluid appears to be salt water, it is clear and salty. (Yeah, I tasted it)

My questions are:

Can I run the engine in this condition assuming I am not worried about the small amount of water. ( should I be?)
Should I just try tightening the drain? Its all plastic and I don't want to break it.

Sorry no pics, phone was dead. Thanks!

[donradcliffe]

That leak will drain down to your bilge to join the water from the other leaks. You should have a bilge pump to pump it overboard. You may want to fix the leak eventually, but it won't sink the boat for about 10,000 hours or so.

[sagablu]

Thank you,

My main concern is not the water, its the engine. Is there an issue with the engine overheating as a result of this leak? Secondly, how do I repair this? Should I try to tighten the leaking drain or remove and reseal?

[Excalibur5]

You have nothing to worry about with the leak overheating the engine. The water goes there AFTER cooling the engine.

As stated before, I would fix it eventually (a little bit of RTV silicone on the fastener or a small O-ring would fix it if tightening it a little does not.)

The fastener is there to enable you to drain down the water lift muffler in the winter to prevent freezing.

If the boat is new to you though, I would recommend replacing the raw water impeller.

[Lepke]

Depending on engine size and condition, it is often better to drain the muffler between uses. 1) less back pressure especially in cold weather when diesels don't start as easily. 2) If cranking the engine more than normal, hard starting, doing maintence, etc., every crank the salt water pump is filling the muffler but without exhaust, little or no water is being expelled. It can back up and enter the cylinder via the exhaust valves or ports. Also during long shutdowns, marine organisms can bloom.
I put auto valves on my water mufflers that drain whenever there is no exhaust pressure.

[sagablu]

Thanks all! That is what I needed.