Screen missing raw water intake - generator

[Sea Wolff]

Here in the Sacramento delta, and probably other parts of USA, have an invasive plant called 'egeria' that grows in water less than 12' deep. It is a long narrow flimsy plant that can get sucked into raw water intakes. I can't tell you how many times I've had to shut down my gen to get the egeria out of the sea strainer and the intake hose. :smt021 Other boats we boat with rarely if ever have this problem.

I seem to recall when I had the boat hauled out a few years ago that there was no screen on my generator raw intake, the thru hull. I was looking at the parts manual [?] for my 390MY, page 93 shows the diagram and parts for the generator system. I don't see a screen on this thru hull in the book either. Am I suppose to have a screen? I talk to other boat owners, Mainship and a Carver and they have clam shells with a small opening that faces toward the bow. Would this work for me?

 

[tbirdvet]

I have no screen on the hull intake. I rely on the strainer to catch the stuff. My thru hull fitting is round with slots.

 

[cod]

On the east coast, we have to deal with sea weed. The solution is a sea strainer that is mounted over the water inlet of the generator and/or the engine raw water inlet. Go to freeportmarine.com and do a search for "sea strainer" or "scoop strainer". Install it and you won't have a problem.

 

[Sea Wolff]

COD - thanks that was what I thought should be on the raw water intake, some type of screen device.

for my reference - do you recall which one you ordered?

Best,

 

[tbirdvet]

Just to be clear you want a strainer and screen inside the boat right after the hull intake fitting. You do not want a screen on the hull fitting outside.

 

[cod]

Not sure but the smallest one they make will be fine for the generator. Be sure to order the one with the removable screen so you can clean/bottom paint behind it when the bottom is painted.

COD - thanks that was what I thought should be on the raw water intake, some type of screen device.

for my reference - do you recall which one you ordered?

Best,

 

[Sea Wolff]

tbirdvet
Re: Screen missing raw water intake - generator

Just to be clear you want a strainer and screen inside the boat right after the hull intake fitting. You do not want a screen on the hull fitting outside.

Tbirdvet - why do you suggest this? From what COD states, and fellow boaters I've spoken to - their screens are on the bottom of the boat.

Best,

 

[tbirdvet]

If the screen gets plugged on the bottom how are you going to clean it off without getting under the boat. Whats the difference if the screen on the bottom gets plugged or the screen in the strainer gets plugged. At least you can get to the strainer screen easily.

 

[cod]

Never happens under the boat. The purpose is to stop anything from being sucked up into the intake. I've installed it on more than one boat and never had a problem afterwards. I run my generator nonstop for several days. Before I installed it, I had some type of sea plant get sucked up and get stuck in the hose, hence no water to the pump and the genny shut down. This prevents having to always check or clean the strainer.

If the screen gets plugged on the bottom how are you going to clean it off without getting under the boat. Whats the difference if the screen on the bottom gets plugged or the screen in the strainer gets plugged. At least you can get to the strainer screen easily.

 

[Alex F]

This is not the best picture, but this is all I had. I took it when was buying my boat. This is what the seastrainer looks like for the engine side that cover the scoop strainer. The one for the generator works the same way, but it's a round shape and it's much smaller.


This picture is also a good example of what happens when a boat is not used much and the marine growth just builds up and creats raw water intake obstruction. In my case, previous owner was selling the boat so he didn't use her for few months.

 

[Sea Wolff]

This is not the best picture, but this is all I had. I took it when was buying my boat. This is what the seastrainer looks like for the engine side that cover the scoop strainer. The one for the generator works the same way, but it's a round shape and it's much smaller.


This picture is also a good example of what happens when a boat is not used much and the marine growth just builds up and creats raw water intake obstruction. In my case, previous owner was selling the boat so he didn't use her for few months.

alex - thanks for the 'extra effort' of posting the picture :smt038

best,

 

[cod]

Alex,
Lets keep it in perspective...., as you state, the boat was not used for several months. Even without the scoop strainer you could have barnacle build-up in the intake hose, along with many other issues such as growth on the running gear (props and shafts). A boat sitting unused for that period of time without doubt is going to have issues. But under normal use, you should not experience that type of growth. Like all things with boating, maintenance an use is paramount.
But lets get back to the original question, how do you minimize the constant hassle of cleaning of the sea strainer. The scoop IMO and experience is the answer.

 

[Alex F]

Steve,

I agree 100%. My boat had propspeed at the props and PO claimed that in his area it help a lot. I never had the need for anything like that on my running gear, b/c (as my wife likes to say) I prefer to spend the money on fuel and run the boat, instead of paying for the bottom cleaning services....LOL.

Regarding those strainers, all I can say that make my boating a LOT easier. We also have lots of eal grass and my 320DA was alsways sufferring from just a little obstruction. One time while I was heading out early in the morning on the 10 day trip, the boat couldn't even get on plane after I picked up some eal grass. The most frustrating part is that I cleaned all strainers the night before the trip. Anyway, I'm extremelly happy that my 420 has these strainers installed. The way these things work their majic is that for the whole season I didn't have to clean a single seastrainer (those that in ER), not even once. The glass was always clean. So, those that issues with eal grass would cure the problem instantly by installing these Barnegat Bay Sea-strainers (or how people call it in LI, Great South Bay Sea-strainers).

A quick and important tip, make sure that the holes in the strainer are free from the bottom paint. After the marina did the bottom job :smt021 I had to poke every single hole in the strainer to make sure that it'll allow the raw water run thru. Man I couldn't wait to get out of that place fast enough.

 

[Sea Wolff]

This is not the best picture, but this is all I had. I took it when was buying my boat. This is what the seastrainer looks like for the engine side that cover the scoop strainer. The one for the generator works the same way, but it's a round shape and it's much smaller.


This picture is also a good example of what happens when a boat is not used much and the marine growth just builds up and creats raw water intake obstruction. In my case, previous owner was selling the boat so he didn't use her for few months.

Alex - is the third screen down on this page - the one you show in the picture? if no, is the one you show in the picture, shown on this web page?

http://www.freeportmarine.com/CGI-BIN/LANSAWEB?WEBEVENT+LC43FDC319739D20084EF065+M37+ENG

thanks

 

[MonacoMike]

My understanding was not to have a scoop on a generator as the water pressure can by pass the valves and fill the cylinders with water. This can be a lot more preassure than the little pump can push, especially if the genne is off and the valve open. MM

 

[Alex F]

Alex - is the third screen down on this page - the one you show in the picture? if no, is the one you show in the picture, shown on this web page?

http://www.freeportmarine.com/CGI-BIN/LANSAWEB?WEBEVENT+LC43FDC319739D20084EF065+M37+ENG

thanks

The link didn't work for some reason. I looked at their site and found what they call "scoop strainer".

http://www.freeportmarine.com/CGI-BIN/LANSAWEB?WEBEVENT+L553020309FE9F400C8C004U+M37+ENG


SBSTRAINER#2 = Sea Water / Scoop Strainer 12-1/2" x 6" for the engines

B/AROUNDSTRAINER = Buck Algonquin Round Strainer Bronze for the generator

SBSTRAINER#1 = Sea Water / Scoop Strainer 6-3/4" x 4-1/4" looks like the one I have for the A/C

Before ordering, call them up and verify, and also check your rig to make sure all will fit fine. But, based on how the parts look and sized it should be what you're looking for.

 

[Sea Wolff]

My understanding was not to have a scoop on a generator as the water pressure can by pass the valves and fill the cylinders with water. This can be a lot more preassure than the little pump can push, especially if the genne is off and the valve open. MM

MM - that was a concern of mine as well. Two of my docket mates, one has a 40' carver and the other guy has a 42' mainship, both have the open part of their scoops facing towards the bow. there boats are many years old with many hours on the gens. I would have thought the scoop facing forward would force to much water pressure in as well, especially on plane, but apperantly that is not the case, at least with their boats.

I plan to purchase a 'screen' with no scoop. I am fortunate to have a Kohler [brand of my gen] authorized service/dealer in the city where I keep the boat. So before ordering the screen I plan to talk to him and tell him my plan to add the screen. If he says no problem I will contact SR and see what size the intake is under the boat so I can order the correct size screen.

Best,

 

[Sea Wolff]

Alex - thank you, that post and details is a big help

Best,