Raw Water Flush while in the water

[Cowboys3310]

Hey all-

I have a 1995 carver Santego 310, with 2 4.3l Volvo penta GS engines.

My port motor is getting warm when I throttle up, just replaced the impeller.

This is my first boat, how do I use a garden hose to flush the raw water system, I think it has some seaweed in there.

Thank you for the help!

[Hoplite808]

My 3227 lives in salt water and I use barnacle buster to flush any growth or build up of calcium, lime, and other minerals out of the system annually. However my boat was repowered with Perkins diesels but the overall process should be reasonably close.

My cooling system flush process in the water is as follows:
1) Close the raw water sea cock for the engine I'm working on.
2) Disconnect the hose from the raw water inlet to the v-drive and then connect a bit of 1 1/4' bilge pump hose to it to act as a discharge line to my work area
3) Disconnect the inlet and output from the raw water pump and use a short bit of hose as a bypass to connect them together with.
4) Remove any anodes in the heat exchangers and replace the plugs.
5) Disconnect the hose from the exhaust manifold that normally feeds the used raw water out to the exhaust pipe from the pipe and then connect another length of hose that is long enough to bring it to my work area on the boat and that end of this hose has a garden hose female connector mounted on it.
6) Connect a garden hose and flush the system for a minute. Then use a small sump pump in a 5 gallon bucket to begin recirculating fresh water from the bucket through the engine with.
7) Add the Barnacle Buster solution to the water and then run the sump pump so the the flow is reverse from normal for the cooling system for about an hour.
8) After the hour, fresh water flush the system and reverse the setup steps to make it ready to use again.

If all you want to do it flush out some seaweed that may be clogging the inlet just disconnect the 1 1/4" line from the inlet side of the V-Drive and use the garden hose to blow water back out the through hull from there.

[buster53]

IMG_1638.JPG

Or you can have one of these made up for your sea strainer. They used to be sold years ago as my boat came with 2 and I had 2 made. I have one on each engine, genset and air conditioning. I can flush anytime I want and makes winterizing a breeze.

Sorry about the duplicates....technical issue...me

[km1125]

Do you have a strainer? Is the suspected seaweed after or before the strainer?

If it got after the strainer (or you have no strainer), then you need to take some hoses apart and run water backwards though the device (like the oil cooler(s) ). You might also be able to use a shop vac and vacuum out some debris once you disconnected the hoses on both sides of the device.

[Cooler]

Take the hose off the the thermostat housing on the inlet side. Remove the hose at the water pump on the outlet side. The impeller will stop any water flow from draining into the bilge. Run water into the hose at the t-stat end. Put the water pump hose in a white bucket so you can see what comes out. Do not apply a lot of pressure, just enough to get flow through the hose. You may want to flush several times, until the water in the bucket is completely clear. If you have the spring type thermostats, check for obstruction in spring. Unfortunately, you will need a new t-stat gasket if you take that apart. Hope this helps. er

[plittle2005]

Is the boat straight shaft or sterndrive? Hours? Raw water or FWC? Where does Volvo say to check for plugging, if sterndrive?

We would need to know this before any meaningful advice could be offered. But if straight shaft:

I do not believe Carver would have built straight shaft boats in the '90's without raw water suction strainers.

If seaweed has been sucked in, you will find it in that strainer.

Also, if you have A/C, and seaweed was present around the boat, the A/C suction strainer would be plugged. If not, then seaweed is unlikely a cause of engine suction problems.

Barnacle Buster is just great, BUT if your exhaust outlet parts are corroded up and plugged with rust, those must be replaced. Measure (IR gun) external temps of the exhaust passages and hoses. If >120 F. beyond the raw water injection point, you have impeded water flow. Then compare with cooler engine.

But if manifolds and riser/elbows have not been changed for many years, if ever, then corrosion is the likely cause.

[km1125]

You should also clarify is this boat is now (or has ever been) a saltwater boat or has (and is) it run in freshwater? That makes a HUGE difference on the condition of manifolds and risers, as well as the type and quantity of marine growth.