Mercury 9.8hp 110.. fails to get water to cool engine

[specialTEXAS141]

Hi.. i have a mercury 9.8 and i changed the impeller and i know for a fact it pumps water.. because when i turn the engine over with a drill with the spark plugs removed water is seen from the tale.. but when engine is running i get fumes and very little water.
After testing to make sure there isn’t a leak in the water tube or pump housing i found a leak that almost seems designed.
In the picture below is where I believe exhaust back pressure is escaping into the cooling system. (The picture is taken from where the lower end would be.. looking up.

 

[racerone]

That is where water is supposed to leak out into the exhaust.-----I suspect and have seen it more than once that plastic washer at the top of the water tube is melted.----Remove powerhead to inspect this.----The replacement factory washer is now a better quality.-----I keep some on hand myself.

 

[specialTEXAS141]

That is where water is supposed to leak out into the exhaust.-----I suspect and have seen it more than once that plastic washer at the top of the water tube is melted.----Remove powerhead to inspect this.----The replacement factory washer is now a better quality.-----I keep some on hand myself.

At first I believed the plastic washer was melted aswell.. but when pressure testing the cooling system.. its air tight when applying a piece of tape over the 2 hole shown above.

 

[racerone]

So you did not inspect the washer at the top of the tube ?

 

[specialTEXAS141]

So you did not inspect the washer at the top of the tube ?

Yes i did inspect the washer.. the seal is good.. and i even removed the power head to double check this

 

[racerone]

Is the water in your test bucket 6" above the impeller ?

 

[specialTEXAS141]

Yes i did inspect the washer.. the seal is good.. and i even removed the power head to double check

Is the water in your test bucket 6" above the impeller ?

About 8- 12.. tested on transom of boat.

 

[racerone]

You installed the correct factory impeller?----Measured to fit the different diameter shaft on these motors ?----Removed exhaust cover ?-----Perhaps there is a hole in it.