1999 yamaha 40 hp 4 stroke oil on skeg

littleflat10

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Dec 26, 2009
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17
hello ive got a 1999 40hp yamaha 4 stroke .have it parked in driveway .i moved it to get to the backyard.so i pulled it on the street and when i pulled it back in the driveway i notice the next day a small puddle of oil under the motor .it smells like gear oil and looks as if its coming for the prop and running down the skeg. any help on what could cause this and how to fix this problem thanks
 

robert graham

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Apr 16, 2009
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Remove prop, clean area thoroughly, wait a day or so, then check the prop shaft seal area for exact location of leak....it could be some monofilament line wrapped around prop shaft and under that seal causing leakage....seal may or may not be damaged/ needing replacement...
 

littleflat10

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Dec 26, 2009
Messages
17
yes sir there was some power pro fishing line wrapped around it after inspecting it and cleaning there is a litlle slit in the rudder seal there ,also there is a spring that it around it thata looks alittle streched what would that part be called and where would you recommend getting it from ....also maybe a how to on how to change this part thanks
 

robert graham

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Apr 16, 2009
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If it was my motor I'd take it to a Yamaha Outboard dealer and let a professional replace that seal, since removal can require special tools and expertise....
 

robert graham

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Apr 16, 2009
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Oh, and that little spring is just part of the seal....to hold the lip of the seal firmly against the shaft...
 

robert graham

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Apr 16, 2009
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Any marine specified 80-90 weight outboard lower unit oil....I use the Walmart brand with no problems....There should be a lower drain screw near the front/bottom of lower unit and another several inches above it which is the maximum fill/overflow screw.....both screws should be slot-head stainless with the lower one having a small magnet in the tip to attract metal particles in the oil...
 

robert graham

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Apr 16, 2009
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Also Walmart sells the little hand operated oil pump to inject the oil in the lower hole until it comes out the upper hole....about $8 for the pump
 
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