Logo
FULL SITE MENU

Flushing a Mercruiser 2004 3.0 in the water

G

gizmolvr

Contributing Member
Have a 2004 mercruiser 3.0 that I will be keeping docked in saltwater this year(from now til october). I have replaced all the zincs, installed a mercathode system, and painted the outdrive. I have been looking since last year for some kind of solution for flushing the motor out using a garden hose at my slip. All of the products I have found either just flush one side of the motor or will not work with the 3.0 merc. Does anyone know of a solution to this issue(store bought or homemade)? Does the engine drain when I shut it down (allowing in air to further corrosion) or does it stay full? Any help is appreciated I have not been able to find anything . I contacted mercury and they stated there is no way to do it. On their website for the 3.0 one of the features is "Easy water drain & flush system is standard"??? I have the drains on my motor but no where is there a flush setup. thanks John
 
Re: Flushing a Mercruiser 3.0 in the water

People I know Just putt muffs on while there boats at the marina, run them, and leave the hose and muffs connected to the boat while not In use, One friend even leaves the hose on trickle constantly, If this helps the unit I do not know... Only time shall tell,

One thing you could do to help Is simply run the unit as often as you can...
 
Re: Flushing a Mercruiser 3.0 in the water

im trying to stay away from the ear muffs as it is hard to reach down there while in the water. Boat is used at least twice a week.
 
Re: Flushing a Mercruiser 3.0 in the water

Install the top of a double "TT" inline w/the water inlet hose. The right side attaches to the seawater inlet side and the left side toward the engine. Install 1/4 turn valves between the top of the "T"s and on each leg. On the left leg install a garden hose connection and a waste hose on the right leg for seawater overboard. Run the engine w/the center valve open and leg valves closed. To flush the engine, close the center valve and open the leg valves and run the engine w/the seawater hose placed overboard. and the garden hose on full force. PVC water valves and pipe will work.
 
Re: Flushing a Mercruiser 3.0 in the water

Let me get this straight. Get a double T, one side of the top of the T has the water coming in from the impeller/water pump, the other end is going to the engine. I assume the top of the double T has to have a valve in it that will divert the water from the waterpump into the right leg of the double T that will be connected to sea water overboard. The left leg of the double T will have a connection for a garden hose which will then feed into the engine and flush when running. Is this correct? This sounds like a great setup, just always need to make sure the valves are always set in correct position when running.
 
Re: Flushing a Mercruiser 3.0 in the water

You've got it. You will have to make the double "TT". You can use 3/4" female garden hose connectors mated to a few inches of clear reinforced vinyl water hose on the legs of the Ts. Dip the vinyl hose in hot water to ease installation. I can't remember the inlet hose ID. Use PVC 1/4 turn valves and pipe; easy to glue together. You may need pipe reducers for the T legs.
 
Re: Flushing a Mercruiser 3.0 in the water

Can you draw a simple sketch of what your describing? The "T" valves in your setup would be 3-way valves correct? So when running the engine normally they are straight through. When flushing they are both diverted basically creating two plumbing routes. One from the stren drive pi kup impeller to the first valve and out of the boat. The other would allow city water Iand through the normal route that the raw water normally follows... Through the risers and manifolds and out the exhaust behind the boat.
 
Bt Doctur said:
Dont dig up old posts from 21 years ago, start your own
Click to expand...

That's kind of funny. Most forums want you to not repost a duplicate topic. I was thinking I'm doing what most Admins would want by keeping it on one thread. I can certainly do that if you're thinking it would help.
 
Back
Top