cleaning a gummed up coolant system

[TraskRiver]

Hey guys. Working with a 1996 merc 9.9 4 stroke with with very low hours over the years it has been in service. Just a few at most. So it has sat most of it's life. Got the carb cleaned up and running good but no water. Purchased new impeller for good measure but to my surprise the original was in great shape. So, I used some pipe cleaner and was able to get down the telltale hole and intake side with no obstructions.. still no water. Then decided to pull the thermostat to check it's condition. As you can see, there is an issue with corrosion in the coolant system. I can get air through the system but not much. Is there a cleaner I can run through it and how? The material seems to be soft and easy to clean so I have my fingers crossed it can be cleaned with some sort of cleaner.

Thanks

 

[Scott Danforth]

salt water motor that was not flushed. you will most likely have to buy a gasket kit and start taking the coolant covers off the power head. I do not know of anything that you can flush and be sure it removed the build up. the only sure way is to physically remove the crud.

 

[Grub54891]

Clr?

 

[enginepower]

drano?

 

[TraskRiver]

salt water motor that was not flushed. you will most likely have to buy a gasket kit and start taking the coolant covers off the power head. I do not know of anything that you can flush and be sure it removed the build up. the only sure way is to physically remove the crud.

Indeed. It spent its whole life in the salt. It has only been ran a hand full of times but non the less... looks as though it was never flushed. I'll try and find a pdf manual that will show the coolant system and pinpoint what covers to remove you are referring too and go about cleaning it manually. Just thought maybe there was a possible method in which a cleaner/solvent could be used. But a visual cleaning is probably the best route.

 

[minuteman62-64]

I have an older Mariner that has spent all of it's (running) life in salt water. I had some of that stuff in the thermostat housing and began using (not trying to start a controversy here, that's just my experience) Salt Away - seemed to change that hard crusty stuff to soft mushy stuff.

Another thought, before you start tearing things apart. Go to your local hardware store and get some plastic tubing and assorted fittings, including a hose adaptor. Drop the lower unit and try squirting water up the water tube, in through the tell-tale and through both openings in the thermostat housing. See if you blast something loose and get some flow. If not, tear in to it

 

[TraskRiver]

I have an older Mariner that has spent all of it's (running) life in salt water. I had some of that stuff in the thermostat housing and began using (not trying to start a controversy here, that's just my experience) Salt Away - seemed to change that hard crusty stuff to soft mushy stuff.

Another thought, before you start tearing things apart. Go to your local hardware store and get some plastic tubing and assorted fittings, including a hose adaptor. Drop the lower unit and try squirting water up the water tube, in through the tell-tale and through both openings in the thermostat housing. See if you blast something loose and get some flow. If not, tear in to it

That's what my plan is. I have one of those hose attachments for blowing up water balloons (thanks kids) that I can attach a 1/4" hose to. I have the lower unit apart and have been able to blow air through the lower intake and it comes out the tell tale, with a few chunks of debri. But then reassemble, drop it in a bucket of water and barely anything coming out the tell tale. Just a sputter which slowly trickled off to almost nothing. Thermostat has been removed during this time. I think I'm going to try the vinegar that I have read about.. it's cheap for now. I'll fill the coolant system with it and let sit over night then flush again. Otherwise Im heading to the marine store for a thermo anyway, may grab some solvent to run through it.

The material seems to be fairly soft as it is. At least the material I am seeing. I removed a chunk from the thermo housing that was about the size of an almond. I was going to put it in a cup with some vinegar to see if it would dissolve it but as I picked it up it crumbled apart.

I know the best thing is take the head cover off and clean all the passages but for now would like to try a solvent flush.

 

[TraskRiver]

No Title

Got time to set it up and run it in a recirculating bath of 50/50 vinegar and water bath for about 5 hours. Looks a lot better and is flowing nicely. I know there is still some build up on the inside and could have some hot spots due to lack of flow in some areas so I will tear it down this winter. Id also like to try some salt-away. But for now it will be used as a back up during fishing season.