1979 25hp lower crank seal help

spacemonkey77

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Nov 16, 2015
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I’m replacing the lower crank shaft seal in my eninrude 25904r 25 hp. The new seal came in today and it’s a little different than the original. I just want to make sure I’m installing it right before I put in the adhesive! In the instructions it mentions a Teflon ring (I assume the orange ring) being the lower lip. The photos in the instructions seem to indicate that the narrow end goes in first but does not get pushed all the way down to the metal lip. If it gets pushed down all the way the metal spring would be touching and it makes the seal extremely tight on the crank shaft! The old one was in fact suspended this way as well.
does this look right?
 

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spacemonkey77

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Well the instructions also call for a seal installer that seems to be unavailable! I’ve yet to find it available anywhere. That’s the big reason I ask since I’ll have to install it by hand.
 

racerone

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I am very familiar with that improved seal.----Installed a bunch of them too.---Have new ones on hand.------Never found that I needed the factory tool.
 

spacemonkey77

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Nov 16, 2015
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I didn’t figure I needed the factory tool. All I want to know is if it looks right in the photos I posted or is the seal supposed to be pushed further into the housing? It seems to me that if it’s pushed in all the way then it becomes too tight around the crank shaft because the spring on the narrow end comes in contact with the housing. I’m just wanting to make sure I’m right in my assumption that it does not go in until it bottoms out?

the old seal had a single ring and was not bottomed out either. Thank you for your help. I’ve never replaced one of these seals before!
 

racerone

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Maybe tomorrow or next week I will have a look at one of these seal housings on a 2001 model.---- To see how it is installed from the factory.
 

spacemonkey77

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Nov 16, 2015
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One more question. If I remove the flywheel in order to replace the top seal. Will it mess up timing?
 

F_R

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Not unless you dink around with other stuff like linkages. Just put it all back like you found it.
 

racerone

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What is this motor doing / not doing that leads you to replacing these seals ??
 

spacemonkey77

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Nov 16, 2015
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Cool thanks. It’s got some oil leaking near the top of the motor. I also had carbon on the drive shaft in the lower unit. Plus the seals are 40 years old. They are the originals. It’s always had a poor idle since I’ve had the motor. Carb cleaning and Adjustments have never improved the idle! The motor sat 20 years or more unused!
 

spacemonkey77

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Nov 16, 2015
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Plus when I do a drop test on the cylinders I get this! It has new coils and a power pack! A coil swap changes nothing! In a past thread on here several people mentioned it could be the seals. I never changed them. I just decided to do it!
 
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spacemonkey77

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Nov 16, 2015
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Will do. Thank you. Yeah I was looking back at the old thread and it was you who suggested I change the lower seal. I just never got to it until now. Thank you for all your help!
 

spacemonkey77

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Nov 16, 2015
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I pulled my flywheel today. Does this look like the top seal is blown? Lots of oil!
 

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