No I leave it in about 2 weeks at a time. i just wanted to clean these in the water so I can test run it afterwords to see if it worked. The bag idea is really smart

Put the ears for flushing on it with a short hose kept above the waterline.

^^^ Agreed. Don't just change the impeller.

Ok so now I have

1. Changed Impeller with housing
2. Replaced H20 sensor
3. Cleaned Sea Strainers
4. Flushed The Oil Cooler & Heat Echanger out with water
5. Back Flushed lots of Hoses off everything

Still have a water pressure issue. Next Step?

My friend said to get a 22 cal rifle cleaner, and run it through the tubes of the heat exchanger. Anyone try this?

Just checking, but you removed the ends of the Heat Exchanger. and made sure all of the passages are clear, correct?
You have all of your cooling coming through the drive, correct? You do not have through hull pickups, correct?
You have verified with SmartCraft or Scanner that the computer's reading of water flow is low on that side correct, just not the
Problem exists 100% of the time, correct? Idle, and when running at different speeds?

One last test while in the water: Start and idle both of your engines. Does the water flow look even across all four exhaust pipes?
The 600SCi, also has separate cooling thru-hulls too I believe. If so, does the exiting water flow look even across both engines?

I think it's time you pull the boat, and start checking the outdrive and transom assembly. I have seen the transom assembly passage and hose on a (33') Baja get so corroded and full of crap that it had to be replaced. You could also have Zebra mussels or other growth in there. I pulled the motor OB motor off of my 17' catamaran and found Zebra mussels that had made their way into the transom bracket's nooks and crannies, that were never visible when the motor was on the boat.

Pull the ends off of the heat exchanger, and look across it with a droplight or sunlight on the other side. You will be able to see if you have blocked passages.
If you can't do this when installed, remove it. and do it on a bench. I feel like you could do this with the boat still in the water as this is way above the water line.

I have not looked through the passages yet. im going to look, and clean them with the rifle cleaner this evening I suppose. I only flushed it out with water so far.

All the cooling is through the drive, and the drive is def not the issue.

The problem is def not in the smart craft it is def a clog somewhere

Yes at idle the boat has very similar water flow on both engines. it only when you are moving and give it more RPM when you notice and see H20 loss on thr smart craft and it put it into guardian

The outdrive is brand new. Does even have 1hr of run time. The transom/drive are already checked.

Just be careful with the 'rifle cleaner' in the tubes of the heat exchanger. They are quite thin brass tubes. You don't want to damage one forcing having to braze it shut, or a replacement h/e. Flushing with water isn't really going to do much as that's all running the boat does: pushes water through them.
It's pretty much mandatory to replace the large flat rubber washers that seal the ends of the Heat Exchanger when you take them off. Make sure you source these from your dealer before you take the ends off.

In looking at a few pictures of that motor online, and knowing how tight the bilge is on a 30' Baja, I don't know if you are going to be able to do much with the ends off of the heat exchanger while everything is still on the boat. Good luck.

I tried this spring but it was too large. Ended up finding a small diameter length of Dowling.
agree with sydwayz on the transom hose.
ok isee this has been checked or changed.

The rifle cleaner was to large? What is Dowling? Do you have the same heat exchanger as the 600sci?

I think it was like 3/16 dowel. Mine was a 502 so it may be smaller, dunno.
did your flow issue happen slowly over time or come on fairly sudden

oops, I read what size dowel. Its wood turned. Think tiny closet rod.

It came on very sudden. Been trying to find it ever since. Also i don't know what a dowel is

Its possible the suction line is bad and collapsing internally.
I edited my last post , but dowel is just wooden roundstock, available at any craft store and most hardware stores.

I got a rifle cleaner kit. Im going to give it a shot. Ill go from there I guess. This is my nightmare :angry-smiley-038:

Was just reminded of another person with similar issue, turned out to be a clamp not fully seated or tightened allowing air to be drawn in as demand increased.
Having strainers l have to believe your issue is on the supply side of the pump somewhere if no impellers have grenaded in there.

Did anyone mention to check the water psi sender also ? They are in a brutal environment as they do not get filtered liquid like an oil psi sender does and they of same exact design and can go bad (plugged) easily.

How did the rifle kit go?

No answer here on my above post. I can definitively tell you that I have seen water pressure issues on more than one Baja with their fresh water flush system getting gummed up.

I cleaned out the heat Exchanger last night with the rifle cleaner. Nothing really came out. I also flushed water straight through, and water seamed to come out of every hole. No dice.. :(

Still have to keep looking

Replaced all the gaskets i could see. Still searching for the issue

Did you check the fuel cooler that is between the sea pump and engine oil cooler?

http://www.mercruiserparts.com/bam/s...1374/11743/140

I dont see where this would be located. The Sea Pump hose goes directly to the Oil cooler

Follow the hose out of the bottom of the sea pump, it should go down under the front of the engine, that's where the fuel pump and cooler are hidden

Have you checked this ? Drive and transom changed . Is the 1 1/4 line from transom new as well. Was this issue there before all this took place?

To be honest im not sure where this fresh water flush system is. I have never used it, and im not 100% sure what to be looking for there. The drives are both brand new with maybe 1hr run time on them. The port side had the problem before I had put the new drive on. I figured I would have found it a lot easier, but its been an on going summer killer for me.

I also haven't seen this fuel pump cooler.

At this point some photos are worth a thousand blind guesses, if you can figure how or text to someone who can put them up someone will find the issue for you.

When you cleaned the strainers, was there anything in them?

You replaced the sensor as well as the impeller and the housing, which none fixed it so the problem is most likely a "clog" in the system somewhere, IMO.

Maybe try removing the water line coming from the drive into the sea strainer and put the water hose in it and check to see if the water flow that comes out of the drive is similar on each side....if it is than the problem isnt on that side of the system.

does you setup look anything like this ?....the fuel cooler and the pump is right below the crank pulley

As to late said , if you can't get to the strainer feed line maybe pull the pump feedline and backflush it to check for a restriction.

yes minus the NXT drive. I will have to check this.

I took the hose off the oil cooler, and started the engine. the water pours out like a fire hose (so the drive is def picking up good water). Also the line that is going into the heat exchanger flows excellent.

We crimped the hose going into the heat exchanger with pliers, and we got amazing H20 pressure. When you uncrimp it it goes right back down. Strange...

I have not been able to find the fresh water flash system, or T that you speak of.

IF your boat is equipped with this, you should have something like this near the top rim around your engine compartment:
[ATTACH=CONFIG]558088[/ATTACH]

I do not beleive I have these anywhere on my boat. unless im blind. my old 30 outlaw had them, but havent seen them on the 600SCI's anywhere

Probably not equipped then as it was a factory option.

No im guessing it does not have that option. Where do you guys think I should go from here?

Have you put the boat in the water lately? What are symptoms are you seeing now? Any different than original symptoms?

With strainers I don't see this happening but I'll throw this out there...

I have twin 496HOs and even pulling the line off the oil cooler and picking at debris there was debris inside. Back washing with just water wasn't enough. A friend screwed together a hose fitting as well as an air tool fitting (think tire valve) which allowed me to add air behind the water as I back flushed the system. I back flushed from the heat exchanger back inlet hose to the outlet on the sea pump. The debris that came out was astonishing. It cleared all the water pressure issues that I had been having in just a few minutes. I had been dealing with debris issues for the past two years.

However, with strainers, I don't see the wood I had clogging my system getting to the heat exchanger. Despite that, maybe adding some air to the back flush would at least put your concern of remaining debris to rest?

yes the boat is in the water now. It has the same symptoms as when I started. I have tested all the water pressure coming through the system, and its flowing like a fire hose! Is it possible air is geting in somehow? maybe i need to tighten the hoses on the sea strainer?