KF 5 lower crankshaft seal

[larrym]

I have a KF5 and want to put in a new bottom crankshaft seal. How do I go about getting the bottom tube off the motor to get to the seal. I have seen several pictures and they always show the block with this tube attached. Is there something internal that is holding it on and you need to take the motor apart? I just can’t believe they would design something that involved to just change seals.
Thanks
Larry Mac

[mercuryman]

Look around the top and you will see a pin, remover it . Put on some leather gloves apply lots of heat and twist it off. I replaces the seal once and will never try it again. I also had to remove the crankshaft.

[Anonymous]

You will need to disassemble the motor and remove the crank. I have done mine and will never touch another one. And still have to deal with the tube. Not a fun job.

[larrym]

Does anybody have any pictures with the tube off? What I am hearing you still need to remove the crank even with the tubes removed. I see the pin that pins the small tube to the larger tube but I can’t see what holds the larger tube to the motor. Is it a press fit? I have a Mercury Master Manual but it doesn’t say one thing about replacing the seals or removing the tube.

[mercuryman]

The large tube is part of the base of block. The top bearing carrier must be removed and the crankshaft pressed out the top with the center main bearing (reed valves). Once the crank is out you can drive out the seal out . Its hard to work down in the tube to install the seal, so that is why you remove the tube ( I am not talking about the water tube) I think Mercury had a tool to install the seal. I used heat around the reed valve cage and was able to just tap on crank and it came out. Everybody should do this once. Also you must remove cylinder block and disconnect the rods.

[Buccaneer]

I took the tube off my Mark 6. I’m not sure if there’s much different
with the KF5. I found a short piece of pipe that fit over the tube
and put a bolt through it. I used this pipe to put my pipe wrench
on to twist after I removed the pin and heated up the bottom of
the power head that the tube goes into. Took lots of heat,
but didn’t take long to get it off.

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[larrym]

Buccaneer thanks for the pictures. Do you have any pictures of the bottom of the motor with the tube out. Just looking down the tube on my motor there is a plate with two screws, would the seal be under this plate? I guess I don’t understand why the crank needs to come out. I wish I had a junk block to mess with just to see what is going on.

[Anonymous]

When I replaced the bottom seal, I did not remove the pivot tube. I worked though the tube to remove the two bolts that hold the cover and both bolts and cover came out the tube and then scraped the cover gasket from the block. Then disassemble the motor to remove the crank. Then tap the seal out the bottom of the block(do not damage the bottom crank bearing) and remove seal through the tube. Reverse the process by installing the seal back into the tube into the bottom of the block, tapping it into place.

[Buccaneer]

Larry, I think that the Mark 6 may be different in that the lower seal
goes into the water inlet cap instead of the block itself.
Anyway, here’s the inside with the "cap" removed.
As said, the job can be done with the pivot tube left on,
but you have to get creative with tools to scrape
the cap gasket surface, remove the cap screws, install
the seal, etc.

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[larrym]

Buccaneer this looks to be like what I am looking at. From what I gather you are right about the seal being in the block while yours as you said is in the cap. So when going back with the tube I guess it is just a press fit with nothing else holding it in place. I am thinking about making a slide hammer and leaving the two tubes( small tube and big tube) together and pull them both at once. I may need to pin the other side of the small to big tube together to keep it from cocking to one side. Still thinking about this project, anybody have any more ideas?

[Author]

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