Rusted cylinders

[jasonschumacher]

I recently purchased a 1955 Lighwin 3hp for 30 dollars. I wasn't expecting a whole lot. To my surprise, it had a new impeller, coils, points, and a few other minor things that look like they were replaced shortly before it last saw service.

Now for the bad. The headgasket blew and that is the day this things stopped running. There is rust in the cylinders.
This in itself wasn't too big of an issue as i was able to remove most of the rust and was left with VERY minimal pitting in only the worst of areas. Nothing a good honing won't take care of.
What is stopping me from going any further are the pistons. The are frozen to the cylinders from the rust.

Will I be able to get these out without destroying the pistons? Everything else is in good shape. The crank looks like it was never touched.
I really don't have the money to spend on new pistons though. (yes I know how cheap I sound)

It has been soaking for 2 1/2 days in PB Blaster so far with me tapping at it with the dead blow every so often with no avail.
Will it move if I am just a little more patient, or are my dreams a lost cause?

 

[jbjennings]

Re: Rusted cylinders

Patience will be your friend. Those little 3's are very hard to find NOS pistons for, and very difficult to find decent used pistons for , but I know of a source if you're in need. PM me. I don't know where you could get new rings. You have no choice but to be patient, really. You might as well split the case and put some oil in from the other side, which you've probably already done based on your description of the crankshaft. Hopefully the rings are seized up in the grooves so badly that you ruin the rings or pistons getting them out, too.
I'm jealous, $30 for a 3hp OMC is a good deal any day!
JBJ

 

[jasonschumacher]

Re: Rusted cylinders

Patience will be your friend. Those little 3's are very hard to find NOS pistons for, and very difficult to find decent used pistons for , but I know of a source if you're in need. PM me. I don't know where you could get new rings. You have no choice but to be patient, really. You might as well split the case and put some oil in from the other side, which you've probably already done based on your description of the crankshaft. Hopefully the rings are seized up in the grooves so badly that you ruin the rings or pistons getting them out, too.
I'm jealous, $30 for a 3hp OMC is a good deal any day!
JBJ

I have found a source for the rings, which I expect will have to be replaced.
And yes I have split the case. It was very easy. Took me about 2 hours to take off every bolt on the motor. Well one bolt did break off in the head, but I think I can fix that.
I have put PB in the other side, but is there another solvent you suggest over PB? I heard ATF works, should I be using that instead?

 

[jasonschumacher]

Re: Rusted cylinders

I was also wondering if I could use electrolysis to remove the rust. I have done it for gas tanks several time very successfully but I didn't know if I could do it for this since it is aluminum?

 

[boobie]

Re: Rusted cylinders

You can mix up some ATF and Acetone 50:50 and try that. Every once in awhile give the pistons a rap with a wooden block and hammer. Patience !!!!!!

 

[1946Zephyr]

Re: Rusted cylinders

Yep, just like boobie says. Acetone and ATF. If the crank is in good shape, that is a huge plus. That will save you about $300 + Mix enough of that stuff, to where you can fully submerge the block in, so it'll creep in better.

Those 3's are awesome little motors. I have the same year Johnson JW-11, myself. It had sat unran for aproximately 20+ years. Good little runner with a fouled carb and bad coils. LOL

 

[jasonschumacher]

Re: Rusted cylinders

You can mix up some ATF and Acetone 50:50 and try that. Every once in awhile give the pistons a rap with a wooden block and hammer. Patience !!!!!!

Will do. Should I be hitting these pistons from the top, or should i fabricate a wood tool that hits them from the bottom out. Eventually I will probably have to make that anyways since they can only come one way, but I don't know if I should hit them the easy way first just to loosen them up.
Thanks for the help you guys btw.

 

[jasonschumacher]

Re: Rusted cylinders

Yep, just like boobie says. Acetone and ATF. If the crank is in good shape, that is a huge plus. That will save you about $300 + Mix enough of that stuff, to where you can fully submerge the block in, so it'll creep in better.

Those 3's are awesome little motors. I have the same year Johnson JW-11, myself. It had sat unran for aproximately 20+ years. Good little runner with a fouled carb and bad coils. LOL

I didn't even see your post there. That looks identical all besides the name, dents and all! Haha. I'm very excited to get this running. Hopefully it will. It's unfortunate about my cylinders since everything else in the motor seemed so well maintained.

EDIT: Wait a minute, does your prop have 3 blades? Is that the standard, because my tiny prop only has 2...

 

[Chinewalker]

Re: Rusted cylinders

For the initial loosening, tapping from the top is fine, but to get them out, you'll need to come in from the crankshaft side. Making a hardwood jig to push on the piston would help. Avoid pushing on the con rod, as they are aluminum and easily distorted.

I think I might have a serviceable used piston or two leftover somewhere if it comes down to that. Not sure on rings, though.

You'll see those motors with 2 and 3 blade props. Most have twos. The three might have been an optional prop? Not a big deal either way... the motors perform about the same with either choice. The 3-blade might have more grunt if you're pushing a larger boat with it.

 

[jasonschumacher]

Re: Rusted cylinders

Ok guys, I have really appreciated everyone's help so far. I have gotten the pistons to move! Unfortunately, I was only able to move them towards the crankshaft. Now that I need to move them out of the cylinder, the area of which I have to place the jig is so small, my jig fails every time.
I'm using two halves of a somewhat rounded piece of wood, but it just gets smashed every time I try.
Do you guys have a better idea for a jig shape? Maybe a different material?

 

[jasonschumacher]

Re: Rusted cylinders

I guess I should update this. I finally got the pistons out. I ended up having to make an aluminum cutout jig at work. It took quite a bit of "persuading" to get them out, but I finally did. They didn't even scratch the side walls on the way out!
Well they were still pretty rusted when I got to examine them without pistons, but it was mostly surface rust and it looks like it should work now that I've honed the cylinders.
I got parts on the way and should be in tomorrow afternoon, so hopefully I can get it running tomorrow night at work.
I'll give updates and pictures if I do.

Also, there was about two drops of water in the gear case when I changed the oil. I took it apart and nothing looked rusted. The bearings could probably be replaced, but definitely are in running condition. Is this something I should be concerned about, or could this have been a result of just sitting for so long? My motor senses are tingling and tell me that a seal might need to be replaced, but I have only found 2 (one is an o ring behind the prop, and the other below the impeller) but neither look bad. Any input?