Exhaust waterline question? - Page 2

chef2sail · #11 11-06-2012

I rememeber when you got her. Youve done a great job refinishing and bringing her back. Now shes part of the family, yours....and the C&C family. I also have enjoyed reading your progression sailing.

Dave

azguy · #12 11-06-2012

Those before and after pictures are amazing, congratulations to you for a job well done....I got a chuckle from the before bottom picture, pretty growthy...

BarryL · #13 11-06-2012

Hey,

One point that has not been made: Make sure that the exhaust flange, where it exits the transom, is properly sealed. On my boat, I have problem where I was ending up with a significant amount of water in the bilge, but only after motoring. I thought it was the stuffing box, it wasn't. I thought I had a raw water intake leak, i didn't. Then I thought that the exhaust was leaking - it wasn't.

The flange that the transom, where the exhaust hose connected to, wasn't sealed. When the transom squatted under power, water was leaking in around the flange. I removed it and properly sealed it. No more water leaks.

Barry

ltgoshen · #14 11-06-2012

Quote:

Originally Posted by BarryL

Hey,

One point that has not been made: Make sure that the exhaust flange, where it exits the transom, is properly sealed. On my boat, I have problem where I was ending up with a significant amount of water in the bilge, but only after motoring. I thought it was the stuffing box, it wasn't. I thought I had a raw water intake leak, i didn't. Then I thought that the exhaust was leaking - it wasn't.

The flange that the transom, where the exhaust hose connected to, wasn't sealed. When the transom squatted under power, water was leaking in around the flange. I removed it and properly sealed it. No more water leaks.

Barry

I have a very water tight boat. The wet packing leaks maybe 6 or 7 drops a min at adle then a little more while the shaft is spinning. The flange in the back dont seam to be leaking at all.

Brent Swain · #15 11-06-2012

I deliberately send my exhaust below the waterline, as that eliminates the need for a muffler. I have a 1/4 inch anti siphon hole above the waterline. Some go down several feet with no problem.

ltgoshen · #16 11-06-2012

Quote:

Originally Posted by Brent Swain

I deliberately send my exhaust below the waterline, as that eliminates the need for a muffler.

How do you know if your impeller stops pumping water if you cant see it spitting?

trantor12020 · #17 11-07-2012

Quote:

Originally Posted by ltgoshen

How do you know if your impeller stops pumping water if you cant see it spitting?

When temp alarm comes on.

ltgoshen · #18 11-08-2012

Being new at this, I have made it a habbit of looking over the stern rail looking for the water to be spitting out the back once I fire up the yanmar. It's kind of scarry to wate on an alarm before you know. I dont want to hurt the engine.
Thanks for the help.

msmith10 · #19 11-08-2012

You're right to do check for water flow every time you start the engine. I suspect that the alarm comment was a bit of sarcasm. Most A4s don't have alarms installed, although they're a good idea as they'll also warn you about low oil pressure. The most common mistake I make when starting (always while sailing, not leaving the dock) is to leave the choke closed. After a few minutes I notice the engine is running very rough. It then takes a while to burn the fouling off once I open the choke. I need to install some kind of "choke alarm."
I noticed you said that your stuffing box leaks at idle. Is this all the time, even when the engine is off? If so, the packing nut probably needs to be tightened a little bit. The short version is, it should not leak when the shaft is not turning but should drip a little when the shaft is turning. If the packing nut is too loose, it will leak at idle. If it's too tight, it will overheat and the packing may be so tight that it scores the prop shaft, making it impossible to get a good seal in the future.

ltgoshen · #20 11-08-2012

Quote:

Originally Posted by msmith10

You're right to do check for water flow every time you start the engine. I suspect that the alarm comment was a bit of sarcasm. Most A4s don't have alarms installed, although they're a good idea as they'll also warn you about low oil pressure. The most common mistake I make when starting (always while sailing, not leaving the dock) is to leave the choke closed. After a few minutes I notice the engine is running very rough. It then takes a while to burn the fouling off once I open the choke. I need to install some kind of "choke alarm."
I noticed you said that your stuffing box leaks at idle. Is this all the time, even when the engine is off? If so, the packing nut probably needs to be tightened a little bit. The short version is, it should not leak when the shaft is not turning but should drip a little when the shaft is turning. If the packing nut is too loose, it will leak at idle. If it's too tight, it will overheat and the packing may be so tight that it scores the prop shaft, making it impossible to get a good seal in the future.

Well it drips with the engine running in netrual maybe 5 or 7 drops a min. Cant tell when in gear but its not too much. Should it be tighten up?
My engain is a 2gm Yanmar 13 hp. it has no choke on it. It starts up with the greatest of ease. No-choking a diesel right? Here is the packing I just had it repacked at Marsh harbor boat works.

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