Thursday, June 5, 2014

Watch out for the 75HP Head Gasket!

Previously UN-beknownst to me but the 60HP power head gasket and 75HP power head gasket are different. The Only difference is the location of the cooling hole that allows the water to circulate up into the motor. Imagine my surprise and chagrin when I fired up the Scott and the motor started overheating.

After a complete re-tear down, I found the culprit. Here is the the 75 HP gasket on my 60Hp base see the hole location in the gasket? The second pic shows the base.

 I ordered a new gasket and they were kind enough to verify I got the correct one this time!
Since I had the motor off I also changed the lower main seal. Mine had a chunk missing. (in the pic below right upper). Laings Outboards had one in stock that was a functional replacement.
The cap is held on with 4 bolts and is fitted into a machined area of the block. It has a small rubber ring to seal it. To remove the cap, remove the bolts and tap the cap to rotate it in the machined area. Then you will expose the bolt holes and you can use a dental pick to lift the cap a little bit at a time. I worked my way around 3 or 4 times lifting a fraction of an inch at a time. Once it's lifted a 1/4" you can gently pry it out.

The new main seal (in the pic above on the right lower) just presses into the cap. Then you can reassemble it and go boating!

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