Weed in Raw water strainer

[z1ppy]

Afternoon,

after a little trip up river a few weeks ago i have noticed some weed in the raw water strainer.

forgive the stupid question but is it a question of simply unbolding the top glass, removing the weed and rebolting? will the raw water system need to be primed after to get it to work again??

its similar to the one attached??

 

[DogWatch]

yes

Don't forget to turn the seacock off

 

[ccscott49]

Should fill up nicely on its own, mine do.

 

[z1ppy]

thank you!! will do it this weekend.

 

[Tranona]

You only need to shut the seacock if the strainer is below the waterline. If it is above, just take the top off and clean. Make sure it is on correctly and that it seals as air can get in a prevent the pump from drawing water in.

 

[sarabande]

the top of the strainer should have been installed above the waterline, so when you take off the top, the water inside should drop to the level of the water outside via the inlet piping (assuming the pipe is not blocked.) If the top is below the waterline, you need to turn off the inlet valve first.

Also, the water in the pipe leading to the engine really should not drain away as the impeller is not rotating (assuming a raw water cooling system).


So when you have cleared the weed out, if you prime the filter body, the water will simply drain away again. Starting the engine is usually enough to draw water through the strainer as normal.

You could prime the filter by closing the inlet valve, and start the engine and at the same time open the inlet valve. The impeller should never be run dry.

 

[z1ppy]

interesting....

So when the boat is lifted out of the water in theory the raw water cooling system should drain to the level of the water inlet?? then when re launched and engine starts it should suck water through the system again...

stainer is above the waterline on the boat so thats no worry.

 

[sarabande]

yes; unless you close the inlet valve, the water in the filter will drain on lifting, but the engine will tend to retain water as the impeller seals against the side of the pump. Some water on the engine side will drain out, depending on the configuration of the pipe work and where the outlet valve is located.

 

[FlyingDutchman]

If you open the seacock and clean the strainer and then close the seacock and fill the strainer with water before closing you don't have to worry about the priming. Do open the seacock before starting the engine!

 

[z1ppy]

thanks for all the replies,

there is not a huge amount of weed in the strainer but more than there should be! i have used the boat a few times since noticing it and engine temprature has been 100 % normal!!

will run the boat up tonight as its being lifted for some work tomorrow and clear the strainer when its out of the water.


Thanks for all the help!

 

[satsuma]

Check the strainer regularly, and clean when you find something! These strainers do stop debris, but I have found weed in the heat exchanger before!

 

[prv]

So when the boat is lifted out of the water in theory the raw water cooling system should drain to the level of the water inlet?? then when re launched and engine starts it should suck water through the system again...

Yep - my berth dries out on most tides, but after the water returns I never have to manually prime the cooling system. The pipe from the strainer down to the pump holds a bit of water to lubricate the pump, and within a couple of seconds it's sucked all the air through from the inlet side and is full of water all the way through.

Pete