[embasun]

Hi Guys
How do you flush water though the engine on a 7.4 v8 is it though the z drive or is there somewhere on the engine thanks

[domraga]

Firstly there are loads of opinions and methods for this, this is what I do and I know it works for me (I run a volvo 5.0GL), others may tell you different but the principles remain the same.

You can use muffs from the drive, but I disconnect the raw water inlet pipe from the pump and I have made a flushing pipe (connected to a hose) which fits on to the raw water inlet side of the pump , then you have no loss of water through the muffs which can happen if they don't fit well. Of course, this stage you have to do with the engine running. To flush back thru the leg, I simply push the hose back into the raw water feed pipe and back flush the drive. This way any debris is flushed back out instead of flushing further into the drive of on into the engine as per flushing via the leg with muffs.
I also use this procedure for winterising, its cleaner than muffs and you know exactly whats gone into the pipe.

Finally, you have to do all this with the boat out of the water to avoid getting flooded by removing the raw water pump inlet hose. There are ways to do this using bungs etc, but I wouldnt recommend it unless you really know what you are doing, or you end up flushing the whole inside of the boat with the lake!!

[embasun]

Originally Posted by domraga

Firstly there are loads of opinions and methods for this, this is what I do and I know it works for me (I run a volvo 5.0GL), others may tell you different but the principles remain the same.

You can use muffs from the drive, but I disconnect the raw water inlet pipe from the pump and I have made a flushing pipe (connected to a hose) which fits on to the raw water inlet side of the pump , then you have no loss of water through the muffs which can happen if they don't fit well. Of course, this stage you have to do with the engine running. To flush back thru the leg, I simply push the hose back into the raw water feed pipe and back flush the drive. This way any debris is flushed back out instead of flushing further into the drive of on into the engine as per flushing via the leg with muffs.
I also use this procedure for winterising, its cleaner than muffs and you know exactly whats gone into the pipe.

Finally, you have to do all this with the boat out of the water to avoid getting flooded by removing the raw water pump inlet hose. There are ways to do this using bungs etc, but I wouldnt recommend it unless you really know what you are doing, or you end up flushing the whole inside of the boat with the lake!!

Thank so much for the info been a great help

[s.a.charlie]

if you bypass the pump in the out drive dont you burn up the impeller in the out drive sounds like a bad idea to me

[Dave]

Hi S.A. Charlie,

Your're right if it's a MerCruiser Alpha drive - the impeller is in the drive - but a 7.4 should be on a Bravo drive so the water pump would be inside the boat..... but we always flush through using muffs on the drive whatever type it is...... but each to their own

Dave

[domraga]

Yes, agree, only use my procedure if you know the water pump is in the engine (as per my volvo), can't speak for Merc's

[ShabahZ280]

Use the muffs... Don't try any other methods if you don't know what you're doing. What are you trying to do, flush out saltwater?

There is a commercially available de-salination kit made by Volvo Penta that sprays a chemical to break down the salt in the water supply. It's called Neutra Salt. When you're finished running your boat, instead of shutting down, you leave the engine running for about 45 seconds and press the neutra salt button. It pumps a chemical through your water inlet that flushes and breaks down salt, and routes it out through your exhaust (underwater). It doesn't harm the environment at all, and in less than 45 seconds, your water supply is completely clear of any salt contaminants, even if you store permanently in saltwater.

QL Neutra-Salt Engine Flushing Kit - Volvo Penta 3808823 - Volvo Penta

[embasun]

Originally Posted by ShabahZ250

Use the muffs... Don't try any other methods if you don't know what you're doing. What are you trying to do, flush out saltwater?

There is a commercially available de-salination kit made by Volvo Penta that sprays a chemical to break down the salt in the water supply. It's called Neutra Salt. When you're finished running your boat, instead of shutting down, you leave the engine running for about 45 seconds and press the neutra salt button. It pumps a chemical through your water inlet that flushes and breaks down salt, and routes it out through your exhaust (underwater). It doesn't harm the environment at all, and in less than 45 seconds, your water supply is completely clear of any salt contaminants, even if you store permanently in saltwater.

QL Neutra-Salt Engine Flushing Kit - Volvo Penta 3808823 - Volvo Penta

Thank Chris will order one tomorrow if they do them in cyprus