Exhaust Not Emitting Enough Water with Exhaust

[sailstoo]

Dunno how long you've had your Cat but if you don't know if it has an impeller that probably means you haven't changed it since you got the boat. Impellers are maintenance items. You pick the period of maintenance but I picked two years for my freshwater lightly used Yanmar. While performing your diagnostics, a new impeller is most likely appropriate. I'd buy two so that I could change it out again in 2013 or so.

[Lowcountry]

Also, be aware that if it is your impeller causing the problem, it is due to your impeller missing one or more vanes. If you don't find the missing vane, you need to check the down-stream plumbing for it before it clogs up a hose.

[motion30]

Originally Posted by sailstoo

Dunno how long you've had your Cat but if you don't know if it has an impeller that probably means you haven't changed it since you got the boat. Impellers are maintenance items. You pick the period of maintenance but I picked two years for my freshwater lightly used Yanmar. While performing your diagnostics, a new impeller is most likely appropriate. I'd buy two so that I could change it out again in 2013 or so.

My thoughts excatly This owner need to do a little research on boat maintance

[John A]

There maybe blockage within the thru-hull value or exterior to this valve.

I shut the value and disconected the hose. When I opened the calve there was a restricted weter flow. I was able to insure that barnacles were not in this brass fitting interior to the valve without increasing the water flow, I had my diver insert an icepick to clean the critters out of the inlet.

If you jave an exterior strainer that has an addditional elbow preventing proper cleaning, you may have to do what others have been forced to do, tale the boat out of the water to replace the inlet to the thru-hull.

[zeehag]

Originally Posted by John A

There maybe blockage within the thru-hull value or exterior to this valve.

I shut the value and disconected the hose. When I opened the calve there was a restricted weter flow. I was able to insure that barnacles were not in this brass fitting interior to the valve without increasing the water flow, I had my diver insert an icepick to clean the critters out of the inlet.

If you jave an exterior strainer that has an addditional elbow preventing proper cleaning, you may have to do what others have been forced to do, tale the boat out of the water to replace the inlet to the thru-hull.

ROFL--i changed mine on my ericson IN THE WATER. is not difficult-- use a friend, a plunger and do the work fast. isnt a bad thing to remain in water-- saves a lot of money and boat wont sink, contrary to popular opinion.

[Lancerbye]

Originally Posted by John A

There maybe blockage within the thru-hull value or exterior to this valve.

I shut the value and disconected the hose. When I opened the calve there was a restricted weter flow. I was able to insure that barnacles were not in this brass fitting interior to the valve without increasing the water flow, I had my diver insert an icepick to clean the critters out of the inlet.

If you jave an exterior strainer that has an addditional elbow preventing proper cleaning, you may have to do what others have been forced to do, tale the boat out of the water to replace the inlet to the thru-hull.

I usually clean all blockages from the inside with a 3 ft. piece of 1/2 in. redi rod I keep just for that purpose. The amount of water that gets in is easily handled by the bilge pump. External strainers are a bad idea.

[ShaunJ]

Originally Posted by motion30

My thoughts excatly This owner need to do a little research on boat maintance

My thoughts are, the owner is doing exactly that, research on boat maintenance on CF. That is why we have a forum, so people can ask questions and get advice.

[SkiprJohn]

Shaun expressed exactly my thoughts.
kind regards,

[swagman]

Originally Posted by swahealy2

John, I follow you when you talk about removing the hose after closing the inlet valve. I can put the hose in a bucket of water to see if it sucks up water. I don't know if I have an impeller or not. The Catalina talks about a design of a wet muffler system that I believe uses the back pressure of the exhaust to draw the cooling water through the engine radiator? Have you experienced this type of exhaust before? Thanks for you quick reply.

Hi Matey,
As others have already explained most engines have an impeller to draw in the cooling water. I doubt your boat is any different.
A wet muffler system is the most common system around. This design mixes the cooling water with the engines exhaust gases as they exit via your exhaust. It reduces noise and helps to keep the exhaust cooler, which in turn reduces build costs as they can make a muffler of plastic / rubber instead of more expensive metal.
But hopefully you've already isolated the actual problem - and fixed it. As I think most who've given advice would like to know what was the real fault was, how about a quick update?
Cheers
JOHN

[sailorchic34]

I've found that, on my boat anyway, its hardened crud where the sea water is injected into the discharge elbow and even in the 90 degree hose fitting that screws into the discharge elbow. I just checked and cleaned mine after 320 engine hours

I use a small plumbing snake to check intake thurhulls. But I've not had a problem with the engine intake side yet. (nicely overbuilt with big big strainer on 1-1/2" bronze reduced down to 3/4" intake hose on the discharge side)