merc 7.5 cooling question

[basstracker54]

I replaced the impeller got good water out pee hole. This was tested in barrel now just below the cover that says 7.5 their are 3 squares recessed in one in the middle is putting out some ehaust smoke? Is their also water that should be comming out? I was told by a guy that if no water my power head is pluged. Of course he told me this after charging 275.00 to replace impeller and now wants another 500.00 to take power head apart. Am I being scamed by this person? I bought the boat last week took to lake and noticed at end of day it was not peeing as it did when first started so tood it in to have water pump impeller replaced/ thanks for your help

 

[ENSIGN]

Re: merc 7.5 cooling question

Take a stiff piece of wire and clean out the pee hole,It dosen't take much to stop it up.

 

[SC1650]

Re: merc 7.5 cooling question

I replaced the impeller got good water out pee hole. This was tested in barrel now just below the cover that says 7.5 their are 3 squares recessed in one in the middle is putting out some ehaust smoke? Is their also water that should be comming out? I was told by a guy that if no water my power head is pluged. Of course he told me this after charging 275.00 to replace impeller and now wants another 500.00 to take power head apart. Am I being scamed by this person? I bought the boat last week took to lake and noticed at end of day it was not peeing as it did when first started so tood it in to have water pump impeller replaced/ thanks for your help

Basstracker,

The water may come out of the three holes after it has cooled the engine, but I am not sure how that works. It does comes out of the tube on the right side of the engine. How are you at mechanics??? This unit is really simple. I just took mine apart and replaced the impeller. It took a few times for me to figure out how to get the thing back together again but I made it. It was also simple getting it back together once I took the time to think about it. Your water pump is run directly off of the engine. The shaft runs straight up to the bottom of the engine from the lower unit. There is a copper tube inside the lower housing that runs up to the power head area. This is the water line that pipes the water to the engine from the water pump. The water goes into a small cavity on the left side of the engine. This houses the thermostat. Mine has a spring type clamp to hold the thermostat and gasket in place. From there it cools the engine, via the thermostat, and goes to the hose running to the pee hole. It is a simple system.

If you want to tackle this let me know.

Steve

 

[basstracker54]

Re: merc 7.5 cooling question

Thanks steve my motor doesn't have the thermostat which was opt for that year 81 It is pumping good out pee hole but the guy who put impeller said my power head was clogged because water was not comming out middle square hole where some exhaust smoke comes out. I marked the head with crayon and ran it in barrel for a good hour and wax didn't melt? thanks any info will help as about ready to sell it. thanks mike

 

[SC1650]

Re: merc 7.5 cooling question

Thanks steve my motor doesn't have the thermostat which was opt for that year 81 It is pumping good out pee hole but the guy who put impeller said my power head was clogged because water was not comming out middle square hole where some exhaust smoke comes out. I marked the head with crayon and ran it in barrel for a good hour and wax didn't melt? thanks any info will help as about ready to sell it. thanks mike

I am surprized that they would cast two separate cylinder castings for the 7.5but so be it. My only thought now would be to try to open up a vent near the cylinder/block casting and try to blow air through the passages. I did this on my unit and it kicked out a bunch of waste/rust, etc. I had about 40 lbs of air pressure to blow out mine. If the wax didn't melt I have to believe that the unit is not overheating at all.

Good luck.

Steve