58 Fastwin seized up

[TinPounder]

everyone, New guy searching for some assistance. I'm in the process of restoring an older 14' aluminum vhull and I've hit a snag. The motor I have is a 1958 fastwin 18 hp model number 15926. The flywheel won't budge a bit. I pulled the plugs and pointed the cylinder up and filed them with seafoam this morning. Some of the fluid has leaked out the exhaust port and it is black lol. I shined a flashlight into the cylinder and man is there a lot of rust inside. I've attached a pic of what I saw. My first question is when is to much rust a sign of it not being economically repairable? I plan on meeting it soak at least a week. Thanks for any insight you can give.

 

[boobie]

Mix up some acetone and ATF 50-50 and pour that into the cylinders.

 

[racerone]

Motor has to come apart.

 

[F_R]

Bad sign. If nothing else, remove the cylinder head, bypass port covers, and intake/reed plate for a peek inside. If you see rust in the crankcase, it needs to come apart or junked.

 

[Chinewalker]

I'd pull it apart. Even if some elixir you pour in there manages to free it up, any rust or pitting can cause damage to bearings, enough so that the motor's lifespan should you get it running can be measured in minutes. Lots of donor motors out there to source powerhead parts from should you decide you want to keep the old motor going.

 

[racerone]

Rings will likely be jammed in the grooves.--------Will simply not run properly.------Shelves are full of " mechanic in a can " because the stuff sells well and generates profit for the makers / sellers.

 

[oldboat1]

always potential for a replacement powerhead. Where are you located?

 

[TinPounder]

I'm located near dayton ohio. I am going to bore scope it tonight when I get home. Motor looks great for being 60 years old. Owner ran it 5 years ago and it's been sitting in his garage since unused.

 

[TinPounder]

Borescope revealed what I feared. The cylinder on the exhaust stroke was solid rust. Couldn't see much on the other since it's up near the top.

 

[TinPounder]

Is 60 # compression good or bad? Just started looking at used powerheads. What should I be looking for compression wise?

 

[TinPounder]

From the looks of what I've read after doing a search I believe that is not. I'm searching marine engine.Com and the model numbers only show for Johnson. Says Johnson /evenrude but I'm unsure if they are the same parts. Only gives me the option of selecting fd12, fde12, fdel12 or fdl12. Mine says it's model number 15926. Any pointers?

 

[oldboat1]

Powerheads should interchange.

 

[boobie]

Is the motor still seized up ????

 

[TinPounder]

It is, when I put my breaker bar on the flywheel nut all it does is tighten and loosen the nut

 

[54bobby]

you should be able to pick up an era specific to match your boat hull motor in good running condition for 150 or less and use your present engine for parts.

 

[Chinewalker]

Make sure you get a powerhead for 1957-1958 model years, as 1959 they added a thermostat and fiberglass cowling, so your cowling mounts won't work. Some guys have fabricated what not to make them work, but for plug-n-play, stick to 1957-1958, Johnson or Evinrude.

 

[Chinewalker]

To further the thought - IF you are into rebuilding it, the GUTS from later 18s will fit within your '58 block. If you tear yours down, punch the pistons out and can hone the cylinders well enough that they're cleaned up and not too hogged out, you can transfer the crank/rod/piston bits from a later 18 into yours. I don't have parts book in front of me, but I'd guess as late last 1967 will work. 1968 & up they went to beefier cranks, 2-ring pistons, etc. so interchangeability gets dicey...

 

[TinPounder]

She's starting to roll over

 

[boobie]

What were you dumping in the plug holes to free it up ????

 

[TinPounder]

50/50 acetone and ATF. The flywheel is turning an 1/8th of a turn so far. Started with that mix this morning.