Mercury 55A 1959 - tips to free up siezed motor.

[Britcheflee]

Hello,

I picked up a 1959 Dorsett Catalina with a mercury 55A motor - the motor is now on a stand and unfortunately it will not turn over - I dropped the lower unit and that is not seized up - I am fairly sure it has the rings rusted to the cylinder walls as it sat for some 7 years outside - what gives me a bit of hope is that when I picked up the boat the motor pull cord was all the way extended out - the recoil was gummed up so it did not recoil so they just left it - this indicates to me that there was at least some time in the past where someone was able to pull the cord and turn the motor over (wishing for a bit of good luck here) - anyway, I have had the thing soaking for 2 days now with mmo, pb blaster and any other spray/lube I can find in there - still will not budge - any other suggestions? I was told to remove the head and use block of wood and mallet to tap piston heads to free up too - what are your thoughts on that and how difficult is removing head/replacing?
Any suggestions welcome!!!!

Lee

 

[wired247]

That cylinder head cover does not allow access to the top of the piston.It does allow access to the outside of the cylinder walls though which is even better. Take the motor apart as far as you can which means splitting the crank case and unbolting the rods if you can. Put 1/3" or so of kroil in the cylinders and get the propane torch to work on the outside of cylinder walls. hot cool , hot cool ad nauseum. Put a wooden dowel into the spark plug holes and start your attempts at freeing it up with a hammer keeping in mind you can buy a used powerhead that turns over for $350 on ebay.