Johnson 90 hp - water impeller stuck on rusty drive shaft?

ib18

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Johnson 90 hp - water impeller stuck on rusty drive shaft? I finally managed to pull the lower unit down and open the water impeller. It was bent and curved. Very dirty around the water impeller. But, how do I get the stuck impeller up and out? I tried spraying PB blaster and used 2 screw drivers to pry it but it would not budge?
 

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Chinewalker

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You're replacing it, right? Bust the bugger off there. Okay, maybe not quite that violently, but you can carefully cut it off the shaft with a Dremel tool with a cutting wheel. Your water pump kit will come with new base plate, so don't fret if you nick that. If you get the hub cut most of the way, you might be able to crack it off with a chisel. Again - slow and easy as you want to avoid damaging the driveshaft.

Once you get the impeller off there, clean up the shaft with some emery cloth or the like.
 

ib18

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yes, I am replacing the impeller. It looks as if the prior owners never changed this thing since 1982??? So much dirty sand in the lower unit. LOL - I just punctured its heart by hammering 2 screw drivers through the beast. It finally gave in and moved from the rusty shaft. I need to sand the shaft down later to get rid of the rust and make it a smoother surface.
 
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Chris1956

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Some of the drive keys for the impellers lock into the impeller hub when the driveshaft turns. Turn the impeller CW, without the driveshaft turning and see if she loosens up.
 

dazk14

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Nice video...

With all that corrosion, how does the gear oil look? The concern here being leaky seals...
 

Fed

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Now would be a good time to check the shift rod height you never know what someone has done before you got it.
Be prepared for cable rigging adjustments when you're putting it all back together.
Do you have the OMC manual for this motor?
 

ib18

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Nice video...

With all that corrosion, how does the gear oil look? The concern here being leaky seals...

Lower gear oil looks really dirty and it has clear water in it. Yes, it definitely leaks water but I will do a pressure test later. I will pressure check the seal after I drain the oil again. I want to test run it in the water and address the hot peeing water first and then circle back to address the leaking lower unit.
 

ib18

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Now would be a good time to check the shift rod height you never know what someone has done before you got it.
Be prepared for cable rigging adjustments when you're putting it all back together.
Do you have the OMC manual for this motor?

no manual but duly noted of the shift rod height. Thanks.
 

ib18

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Some of the drive keys for the impellers lock into the impeller hub when the driveshaft turns. Turn the impeller CW, without the driveshaft turning and see if she loosens up.

ok, I will try that when I drain the lower unit oil again and open up the impeller next time.
 

ib18

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photo217616.jpg
Now would be a good time to check the shift rod height you never know what someone has done before you got it.
Be prepared for cable rigging adjustments when you're putting it all back together.
Do you have the OMC manual for this motor?

This shaft seal (circled in RED) in the picture is clearly broken and letting water in??? Right?

I will buy a seal kit now, and do the pressure test after I water test the motor and drain it again to check water leak.
 

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ib18

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do I really need to smooth out the 3 cut in drive shaft.jpg cuts/groves in the drive shaft where the impeller is sitting before I stall my new water pump today? Please help. thanks
 

racerone

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Those grooves in the shaft are the least of your worries.---Simply ignore them.---They do not affect operation of your wonderful motor or your waterpump in any way.--Very easy to remove the 4 bolts and the bearing housing to replace the 2 seals found there !--Remove the shims and the upper thrust bearing for inspection and posting of pictures.--Love to see them.
 
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ib18

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wow, thanks for the super fast reply. Ooops, I just ordered the seal kit and SAE 90 this morning. Should have done that sooner so I can replace them this weekend before I install the water pump. yes, I intend to do a pressure test, remove those 4 bolts and remove prop and replace all seals (drive shaft side and prop side) when I drain my lower unit oil again to check for water in the lower unit. Mystery will be revealed then. Now, I am just going to install the water pump and test the motor again for hot water peeing. I may need to order thermostat if the water coming out of the pee hole is still hot and burning hands.
 
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ib18

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Mayday, Mayday Mayday - I broke my alumni surface where my water impeller is mating with because I was curious too and decided to unscrew the 4 bolts and used my screw driver to try to pry the plate under the water impeller open - Oh Oh broken allumn.JPG
 
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racerone

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Easy fix with epoxy , again no need to worry about a little damage like that !!
 

V153

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Ya that's not bad. Not good ... but not too bad. Clean the surface'n scuff it up good then marine tex. Mebbe use a piece of something on the inside to act as a form?
 

V153

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Ya that's not bad. Not good ... but not too bad. Clean the surface'n scuff it up good then marine tex. Mebbe use a piece of something on the inside to act as a form?
 

ib18

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yes, Epoxy did the job and water pump is installed, to be mounted back to the motor next. Is this water pump in the right direction? smIMG_8162.jpg smIMG_8166.jpg
smIMG_8172.jpg
 

racerone

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The correct way to install an impeller is to. #1 put the key on the flat with some grease.---# 2 install the impeller on the shaft.---- # 3 verify that key is driving the impeller.----# 4 lower housing onto the impeller while turning driveshaft the way the motor turns it.----Easy as can be.
 
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