Maybe the water that sits between the top of the waterlift and the end of the exhaust hose has drained out and the system is just filling back up?

 

Hmmm, I had not thought of that...I'll have to go below and check out the configuration of the hoses. However, my impression of the situation is that if I turned on the engine after sailing and just let it run in idle then I would not get water coming through. But, if I turn on the engine and increase the throttle, I do get water through. Seems to me if it was just a need to fill the waterlift back up then I would get water either way, just maybe a bit faster at higher RPMs?

 

How old is the heat exchanger?

 

It's original, so nearly 29 years.

 

Try not tilting the boat whilst sailing.
The big water thingy should be in the centre of the boat aligned fore and aft (i think) but it may still leak out if you jiggle the boat.
Then when you restart the engine it has to fill the big water thingy again.

But, of course, maybe I'm wrong

 

Hey Mark,
I can keep the boat from tilting when I'm just running the engine. But I soon as I use that vertical clothesline gizmo to haul up that big white flappy thingy, the boat starts to tilt. Haven't found the adjustment yet to stop that from happening. Although the screaming from the crew does tend to be distracting, so maybe that's why I haven't figured it out. So, I'll try not jiggling the boat so much and see how that works.

Seriously, it may be as you suggest, but I would have thought it would result in getting water splashes in either idle or higher RPMs, although maybe take longer in idle? That doesn't seem to be the case. But I could be all wrong and probably am.

Thanks!
Jim

 

Sometimes, pump efficiency is reduced by wear of the faceplate of the pump. Flipping the plate can restore efficiency if it hasn't already been flipped in the past.

 

Currently has a Speedseal cover (was on the boat when I bought it 2 years ago), so it cannot be flipped. But I'll check that and if I see any wear I'll try replacing it and see if that helps. Thanks.

 

There is some momentary lapse between when the engine starts and the water starts flowing out. I can hear the water/exhaust rumbling up through the system. seems like it takes a few seconds or more for the flow to be consistent, and tends to sputter and cough and does increase when throttle up. I'm not sure it ever does the same thing...Sometimes I'm thinking come on baby...as I'm reaching for the kill switch....but it always seems to cough it up.

 

When you on a tack and the boat is leaned over hard, the water may drain out of the engine cooling intake. It takes longer and needs higher revs to re-establish the flow.

 

Engine zincs(is any) been replaced..?

 

Yup.

 

Do you own the engine's shop/owners manual?

 

Sounds like something may be wrong. By the time you get to the stern to check for water coming out, it should be there. Maybe you have a large water muffler that's leaking down? Other than that, I'd suspect the pump tolerances as mentioned already, a clogged heat exchanger or riser. Maybe pull the hose off the riser and check it there. Just let it drain to the bilge for a few seconds to see if there's good flow to that point. The riser itself may be restricted by rust.

 

I have a 1986 Westerbeke 27 and always motor on and off the dock. When I start the engine at the dock, I normally get exhaust water splashes right away, even if the boat has been sitting for a couple of weeks.

However, frequently when I start the engine after we've been sailing (in preparation to return to the dock), the only way I can get the exhaust water splashes is to rev the engine up high. (The engine starts fine in idle, but the pump will not suck up water at that speed.) It's as if all the bouncing around while sailing causes the pump to lose its prime and it cannot re-establish it without the engine being at a higher rpm. The impeller has been replaced and is fine. I've checked for blockages and there are none. My mechanic does not seem to be concerned, so maybe it's normal. I just do not recall having to do this on my prior boat, which had a Westerbeke 21, and I'm afraid that I'm putting unnecessary stress on the impeller.

What's a reasonable expectation for the raw water pump?

Did you notice any engine temperature oscillations?
Keep an eye on it, I am not sure if you have a problem. Maybe you just have a large water lift. If the engine gets hotter than normal (make a note what normal is) when you turn it on after sailing and before you rev it up, then start looking at the elbow for blockages or the HS. BTW I just removed, cleaned and pressure tested my Westerbeke HS, not a big deal.
Again, the above is only applicable if the engine is running too hot.

 

However, frequently when I start the engine after we've been sailing (in preparation to return to the dock), the only way I can get the exhaust water splashes is to rev the engine up high. (The engine starts fine in idle, but the pump will not suck up water at that speed.) It's as if all the bouncing around while sailing causes the pump to lose its prime and it cannot re-establish it without the engine being at a higher rpm.

What's a reasonable expectation for the raw water pump?

I've learned that when we go out, I have to close the seacock for my air conditioning water pump or it will loose it's prime. Not always when under power, but always if we are under sail.

 

Take a look at this drawing. There are two 'normal wear' items that can affect the pump performance, the wear plate and the cam plate. Many pumps do not have a wear plate, so when the impeller wears the housing it's time for a new housing. Most raw water pumps that I have see have a cam plate. When it wears away the 'trapped volume' does not change as much as when the cam plate was full thickness. Check it out.

Guy

 

Thanks for all the tips. What I'm taking away from this so far is that the situation could be "normal" or could indicate a problem.

After I launch in a few weeks, I'll open up the heat exchanger and look for potential blockages there and elsewhere. I'll check for wear in the pump itself. I'm pretty sure that there is no "wear plate" unfortunately. I'm confident that I could identify scoring in the cover plate, less sure if I could id other types of wear. I may also replace the hoses between the seacock and the pump to eliminate the possibility of a small air leak causing the problem.

Again, I very much appreciate the helpful suggestions.
Jim

 

I had a similar problem with the pump on my previous boat. Pump cover was scored annd filing it flat fixed the issue.

 

JimsCal....thanks for the tip. Right now there is a speedseal cover installed, so I don't think I'm able to file that. However, I believe that in the parts box there is the original cover. So I might make sure that is flat and then try reinstalling it to see if it makes a difference.

 

My Sherwood G6 fitted to a Perkins 4.108 has a flow of 1.2gal/min at 2000rpm. At idle its very little.