Transom Motor Flush

[Nitrousbird]

Are you sure you got it cleaned out well? I hooked a shop vac to mine to suck out everything I could.

[wakeparadise]

Questions that come to mind (maybe too many):

Is it still overheating on the water, or have you only tried it on the hose?

When on the hose, do you have the hose wide open so you get lots of flow?

Is your hose a mile long with lots of kinks in it?

When you found debris in the raw water pump, did you remove all of it?

How long does it take to overheat now?

How hot is the water coming out of the exhaust flappers?

The raw water pump is capable of moving about 60 GPM when the engine is running fast, so you can see how it could starve if you have poor flow from your hose. I think that may be a contributor at this point.

Hi. I haven't tried it on the water (yet) but in the past I was able to maintain 160F on the hose-alone. There are no kinks and there's plenty of water flow. It takes about 5-7 minutes to over heat now. Before it would almost spike up to fast, now it's a steady climb. I'm going to go run the engine right now and check the temperature of the water coming out of the exhaust. If it's cold does that mean the thermostat isn't opening?

[Levi900RR]

How does your impeller housing look?

[wakeparadise]

Questions that come to mind (maybe too many):

Is it still overheating on the water, or have you only tried it on the hose?

When on the hose, do you have the hose wide open so you get lots of flow?

Is your hose a mile long with lots of kinks in it?

When you found debris in the raw water pump, did you remove all of it?

How long does it take to overheat now?

How hot is the water coming out of the exhaust flappers?

The raw water pump is capable of moving about 60 GPM when the engine is running fast, so you can see how it could starve if you have poor flow from your hose. I think that may be a contributor at this point.

Hi Gary,

OK, I brought it out on the water, same thing. The temp slowly climbs and keeps climbing. It takes awhile to do so, about 10 minutes but I shut it off at 190F. The water coming out of the exhaust flappers is "luke warm" (not hot, for sure). I removed ALL of the debris from the transmission cooler screen and the hose to the impeller.

On the thermostat housing itself there are 6 hoses to it. I have attached a picture of an Indmar 350 to show you which hoses were hot/warm/cold as maybe this will help diagnose what kind of problem I'm having. Here is the link for it

[wakeparadise]

Update...

I removed the thermostat completely to see if it would overheat and to try to diagnose the problem further. The engine would stabilize around 160... at times going up to 170 and then diving down 145 and then back to 160...

Is this not a little high temp considering the raw water going in is about 45F? I thought it would stablize around 125... Also, I checked the new tstat and the old one and they both seem to open and close fine in water on the stove...

So confused. Where to go next with this I'm unsure.. could it be the engine driven water pump?

[justgary]

Is your temperature sender on the thermostat housing? If so, you need a gasket with a metal rivet to make an electrical connection between the block and the sender.

[wakeparadise]

Is your temperature sender on the thermostat housing? If so, you need a gasket with a metal rivet to make an electrical connection between the block and the sender.

Hi Gary, No, it's not There is nothing electrical on the thermostat housing.

[shawndoggy]

Time for a vinegar flush?

[formulaben]

Wakeparadise, any resolution on this?

[wakeparadise]

Wakeparadise, any resolution on this?

Yes! The circ pump housing I was using for my heater was installed 180 degrees wrong and was driving hot water back to the block causing it to overheat. Works great now!

[UtahBoatCrew]

My flushpro broke in half and I don’t go in salt water. Can I just remove it and splice the 2 hoses together with no problems until I can get a new one?

[wakeparadise]

100%. This exact same thing happened to me in June. I removed the flush-pro and installed 1-1/14” (I/D) hose to suffice until I got a new one 

[UtahBoatCrew]

5 minutes ago, wakeparadise said:

100%. This exact same thing happened to me in June. I removed the flush-pro and installed 1-1/14” (I/D) hose to suffice until I got a new one 

Would this be why I was starving my exhaust manifolds of water and they were overheating?

[wakeparadise]

Well the engine (block) would overheat almost immediately if there wasn’t water passing through this hose... this is your raw water intake line

[justgary]

16 minutes ago, UtahBoatCrew said:

Would this be why I was starving my exhaust manifolds of water and they were overheating?

Even a crack in your raw water inlet will suck air and impair the cooling capacity.  It may have been cracked for a while before it broke in two. 

[UtahBoatCrew]

Thanks as always for the help guys!