Grease Gun Method

[Aidan Smith]

I am currently contemplating different ways of unseizing a piston from a cylinder of a 1929 Foldlight. The cylinder and rod have been removed from the crank, however I am unsure of how to go about removing the piston. I have heard many different methods being used, from freezing the cylinder to using a grease gun. Has anyone tried these methods, and if so, how successful are they? And if there is a better way, please let me know!

 

Thanks,

Aidan

 

"Shells sink, dreams float. Life's good on our boat."
1921 Elto Light Twin
1923 Evinrude Model N Sportwin
1930 Johnson F-50
1956 Johnson JW-12R
1956 Johnson CD-13A

[Waunnaboat]

Not particularly for outboards, but I have heard that a mix between some sort of cleaner and diesel or something along those lines works well.  I would try some sort of chemical mixture as long as you are doing a cosmetic restoration.  I will ask some of my friends that are more “gear heads” than I am to see what the particular mixture was.

"Outboards seem to multiply exponentially..........I find that for every finished project, there are two more waiting to be completed."

1 user thanked author for this post.

Aidan Smith

[Aidan Smith]

Waunaboat,

I plan on doing a full mechanical and cosmetic restoration on this one, do you know of any known tricks for the least amount of damage?

"Shells sink, dreams float. Life's good on our boat."
1921 Elto Light Twin
1923 Evinrude Model N Sportwin
1930 Johnson F-50
1956 Johnson JW-12R
1956 Johnson CD-13A

[joecb]

A lot depends on how much of a hurry you are in.   If no hurry, repeated soaking alternating with heat cycles may free the piston. with no damage. As for the “grease gun” this works best if the piston is stuck up near the top of the cylinder where no ports are open. One will need a custom made fitting… grease gun Zirk into a spark plug body.

With the slow soak method it’s helpful if the spark plug hole is inline with the cylinder, thus allowing inscrtion of a wood dowel and tapping the piston to get movement.

Your favorite “soak” penetrant oil or ATF fluid.

Joe B

 

1 user thanked author for this post.

Aidan Smith

[Aidan Smith]

Joe,

I’m intrigued by the “heat-soak” method, any recommendations? I am not really in any rush, just would eventually like to get it turning. Also, for the connecting rod bolts, is there a specific torque I need to run on those, or just as tight as I can? Those are the only torqued bolts I am worried about. This motor came to me in pieces, so I am unsure if there are bearings or any needle bearings that go between the connecting rod and the crank. Would you have any ideas?

"Shells sink, dreams float. Life's good on our boat."
1921 Elto Light Twin
1923 Evinrude Model N Sportwin
1930 Johnson F-50
1956 Johnson JW-12R
1956 Johnson CD-13A

[Waunnaboat]

pour 1/3 atf (attomatic transmission fluid), 1/3 acetone, and 1/3 diesel into the cylinder.

"Outboards seem to multiply exponentially..........I find that for every finished project, there are two more waiting to be completed."

[Tubs]

I tried grease gun & compressed air, but this was the only way I could get this one out. Video link – https://youtu.be/QcAwNp0mzRs?si=_36E59BBRauigDdN

A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.

[wedgie]

https://www.aliexpress.com/item/32968101451.html?mp=1

m14 x 1.25 mm is the one you want. Use with consideration.

[Sam M.]

Yes the grease gun method does work.  I have a motor where the grease gun method was used by a previous owner, and it worked until the grease started to escape from the ports.  It might be possible to seal off the ports with sheet metal and gaskets and keep going, but in my case, the pistons were pushed over rusty areas of the cylinder wall, which is not helping me unseize the pistons.  Nonetheless, I would definitely recommend the grease gun method once the cylinder walls are rust/corrosion-free.

Some advantages to the grease gun method include:

• It gives uniform pressure on the top of the piston.  The grease is pushing everywhere, unlike hammering a wooden dowel on the piston, which would only put pressure on the middle.  –   Side note, if possible, avoid hammering on the piston unless it’s a last resort because if the piston doesn’t want to move, the hammer’s force (use wood in between hammer and motor) may push the metal of the piston outwards (towards the cylinder wall, as the metal has to go somewhere) if the piston won’t move downwards, thereby widening the piston and making it harder to take out.  However if the piston can move and is just tightly in there, gentle taps with a rubber mallet alongside penetrating oil should be ok.
• Grease does not dissolve metal.  Trying various mixes of fluids risks the possibility of some metal getting dissolved on a small scale, which could reduce compression.  Think vinegar, for example.  Eventually as it’s acidic, it will consume small metal shavings.
• No heat is needed so there’s no risk of deforming any parts or affecting the factory’s heat treatment to the metal.  Sadly, I have personally witnessed a seized old outboard part become unuseably warped due to overheating and applying pressure while the part was hot.
• You are forcing a lubricant into the system.  That’s helpful when dealing with a seized part😄

 

[Waunnaboat]

Waunnaboat wrote:

pour 1/3 atf (attomatic transmission fluid), 1/3 acetone, and 1/3 diesel into the cylinder.

That mixture will probably work for almost anything that requires a penetrating oil of some sort.  I found some info on it from some other online forum:

Machinists Workshop Mag published some information on various penetrating oils that I found very interesting. a subjective test of all the popular penetrates with the control being the torque required to remove the nut from a scientifically rusted environment.

*Penetrating oil ………. Average load*
None ……………………… 516 pounds
WD-40 ………………… … 238 pounds
PB Blaster ……………….. 214 pounds
Liquid Wrench …………… 127 pounds
Kano Kroil ……………….. 106 pounds
ATF*-Acetone mix……………53 pounds

The ATF-Acetone mix was a home brew mix of 50 – 50 automatic transmission fluid and acetone.

Note the home brew was better than any commercial product in this one particular test.

That mixture probably works for anything where you need to remove rust, penetrate carbon buildup, and pretty much anything else along those lines.  It will be my go to the first time I have to free a piston or rusty bolt or clean a really gunked up carburetor.  I have not had to do much work along these lines with any of my engines; however, that mixture is what I know one of my friends, who while not particularly into outboards, knows more about engines than anybody I have ever met.

"Outboards seem to multiply exponentially..........I find that for every finished project, there are two more waiting to be completed."

1 user thanked author for this post.

Sam M.

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