Blowing out coolant line 4HP Mercury (chewing up impellers)

[huffduf41]

Hi, noticed my outboard wasn't "spitting" water so replaced impeller that was torn to pieces. Put new impeller in and that one also got shredded so pretty sure my coolant line is clogged. Anyone know a good way to clear the coolant line? As you can see below the hole is less than ideal.

Thanks

 

[FLATHEAD MAC]

Re: Blowing out coolant line 4HP Mercury (chewing up impellers)

drop lu again and blow compressed air back thru the tell tale, thus blowing the debrie back out the way it entered,

alos check water pump housing expecialy the cup that the impellar rides in, for scoring and other possible damage, might be good insurance to replace whole housing.

CAN YOU POST PICTURE OF SHREADED IMPELLAR AND HOUSING ??

 

[huffduf41]

Re: Blowing out coolant line 4HP Mercury (chewing up impellers)

Thanks I'll try blowing it out tonight and take some pics of the housing.

 

[CharlieB]

Re: Blowing out coolant line 4HP Mercury (chewing up impellers)

The impeller shredding is often caused by a lack of water supply to the pump, double check the water inlet side of the pump to be sure the inlet screen is not restricted any and if your model uses an inlet side tube from the screen to the pump, that it fits correctly.

 

[huffduf41]

Re: Blowing out coolant line 4HP Mercury (chewing up impellers)

Took the lower unit off and tried blowing out last night w/ an air compressor at 120-psi and couldn't get air out the inlet...it's really plugged. Anyone know of any tricks to unlodge whatever is blocking it? I shined a light up the inlet and can't see the blockage.

 

[CharlieB]

Re: Blowing out coolant line 4HP Mercury (chewing up impellers)

Ahhhh, what are you trying to do in that picture?

Please post a picture of the water pump, you will need to take the pump apart again to clear the passages, post the pic and we can direct you better from there.

 

[huffduf41]

Re: Blowing out coolant line 4HP Mercury (chewing up impellers)

Trying to blow out the coolant line. The lower unit is removed and when I blow air into the discharge (above) nothing comes out of the intake tube/line that is fed by the water pump. The line is clogged bad and I have no clue how to clear whatever is in it.

Thanks.

 

[FLATHEAD MAC]

Re: Blowing out coolant line 4HP Mercury (chewing up impellers)

LOOKIN AT YOUR FIRST PICTURE. THER IS A PASSAGE HOLE TO THE RIGHT GOING UP TO MOTOR , LOOKS LIKE YOU ARE BLOWING FROM THE WATERPUNP SIDE, WHICH WILL KEEP BLOCKAGE IN PLACE.POSSIBLE BLOCKAGE UP IN THERE ,HAVE YOU TRIED BLOWING FROM THE OTHER END,THE PEE HOLE FROM THE COWL SIDE. MIGHT TRY FISHING A THIN WIRE AND "CAREFULLY" PROBE .:facepalm:

 

[huffduf41]

Re: Blowing out coolant line 4HP Mercury (chewing up impellers)

The hole shown above is the discharge. I tried fishing a wire but it's quite a maze....couldn't get very far.