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Johnson 30 HP water pump tube question..


bulletbob

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Water pump failed horribly at Cayuga.. melted  the housing into a blob, blew the head gasket.. Replaced the gasket, thankfully motor starts and seems to run ok...  When I pulled the pump and copper outlet tube, I noticed the upper grommet was burnt to a crisp from the heat.It seemed to just flake apart.The tube fell out on the ground, and they usually stay inside the lower unit housing.. I was told the grommet at the power head side is the same as the one in the pump housing.. It would seem then all I have to do is stick the new grommet on the copper outlet tube, get it secured  and then install everything else normally.. Its really tough to see all the way up in the motor through the shaft housing, but I don't see any damage, and I'm hoping I don't have to pull the power  head  assembly to replace a little rubber grommet.. anyone have any insight into this?? Replaced a LOT of impellers over the years, never had an issue where I had to replace this upper grommet. Hoping someone has done this before and can help me out with some info... bob

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Don't know if this applies to your motor.  There is one video showing how to replace top housing water seal without taking the power head off.  Its titled, '35 HP MERCURY OUTBOARD IMPELLER & WATER PICK UP TUBE FIX'.  Worked on my 60HP after melt.

 

Was looking at online diagrams but they ask for serial number n' year.

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  • 4 months later...
On 6/22/2023 at 12:33 AM, RiggerRob said:

Don't know if this applies to your motor.  There is one video showing how to replace top housing water seal without taking the power head off.  Its titled, '35 HP MERCURY OUTBOARD IMPELLER & WATER PICK UP TUBE FIX'.  Worked on my 60HP after melt.

 

Was looking at online diagrams but they ask for serial number n' year.

Hey is yours the 3 cylinder?   I’m having the same issue. Figured it was a split in the pipe itself

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If you can, turn the engine upside down  or at least horizontal so with the help of a flashlight you can see what's going on at the bottom of the engine block. That may save you from having to take the exhaust off the block.. it will also help you to insert the cooling water tube correctly into the hole.

 

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Fixed this problem MONTHS ago!.. I used a grommet from a pump kit[had to buy and entire 2nd kit just for the 1 grommet, its ok, bought  it cheap online].. The upper end [power head side] of the water tube grommet is the same, it fit fine.. Only thing is the lower end[water pump end] grommet has 2 little nibs one on each side that fit into the  pump housing to hold it secure.. Not sure the upper grommet is supposed to have the nibs,, In any case, I used the grommet as is, nibs and all, and it  put it on the water tube with just a bit of lube, and it went into the power head water outlet hole just fine, and stayed there while I installed the lower unit etc.. water is pumping just fine, had the motor out a few times, no water pump issues.. However, the motor was already pretty tired even before the meltdown, and there was some evidence of aluminum melting in the combustion chambers.. The engine only starts cold with a bit of starting fluid, runs ok at speed, but barely idles anymore.. Really really tired now, and needs the cyls honed and new rings... 2 strokes aren't like 4 strokes.. Once compression gets lower, they are tough to start, and don't idle well, cough a lot etc..  I think I had about 90 PSI each cyl, which is enough for the motor to run, but not enough for it to run and start as it should.. Deciding now if I should tear it down and re ring/hone,, or just find a  known good powerhead.. Parts these days are insanely overpriced, and getting harder to find.. bob

Edited by bulletbob
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