Well that tears it! It locked up!

[Gas Giant]

Engine: Evinrude Lark III 40hp, Model# 35524

Well, due to life getting in the way, its been a few weeks since I've worked on the engine. I was resealing the lower unit, and a friend got cancer and a few other things came up so the engine sat.

So, yesterday, I went out to pull off the hand starter, because I didn't do something right and it doesn't work. After pulling the pull-start contraption off the motor, I noticed the flywheel wouldn't budge. Not a bit, it was frozen solid. Which struck me as odd, because maybe 2 months ago - perhaps a little less - I actually had the engine running for about a minute.

I was confused about how an engine would lock up with only 2 months of sitting. It was covered up.

Today I pulled the powerhead and after getting it on my workbench in the garage, I pulled the head. (They both came off quite easily, no stuck bolts). Well, the top cylinder was rusted surprisingly badly, while the bottom cylinder didn't have any rust at all. The head gasket had no obvious damage, so I am really confused about how water got into this cylinder.

But, my actual question is, does anyone know where to get pistons for this engine? Specificallly, oversized pistons as I am confident that this cylinder will need to be bored out? (Actually I'll probably get both cylinders done since the bottom one appears to have some scratches) A quick google search didn't bring up much.

I'll post pics later tonight or tomorrow of the rusted cylinder, for those that like pics of engine carnage.

 

[levi_tsk]

Re: Well that tears it! It locked up!

whats your model number?
its quite possible that your head gasket was leaking and thats wht caused the rust ... it only needs a tiny amount of water in the bore to get ALOT of rust

post up ics of you head gasket (both sides ) and the bore including the block mating face where the head gasket rides

 

[tx1961whaler]

Re: Well that tears it! It locked up!

I'd hone the cylinders with a deglazing tool to get rid of the rust before I'd assume the worst. The water may have come from a leaking head gasket or from the exhaust covers.
A 35524 is a 1961 40 hp
0.025 OS Piston and Rings are available at marineengine.com
Piston is 378358
Rings are 378433

 

[lindy46]

Re: Well that tears it! It locked up!

Might as well pull the exhaust cover and see what's going on there.

 

[Gas Giant]

Re: Well that tears it! It locked up!

All good suggestions. I'll post some pics tonight after I get home. I have a cylinder hone from when I rebuilt the 283 in my Bel Air, I'll try that.

I'll have to get the piston out first, I'll probably find a way to stand it up so I can pour Marvel Mystery Oil or some kind of penetrating oil in the cylinder and let it sit. I've read dozens of conoctions for freeing up stuck engines, not really sure what the best is.

 

[lindy46]

Re: Well that tears it! It locked up!

A lot of folks here recommend a 50-50 blend of ATF and acetone.

 

[F_R]

Re: Well that tears it! It locked up!

Don't order anything till you look at the bearings. They probably are rusted too.

3 chief reasons water gets in to cylinders:

Head gasket
Exhaust covers and gaskets
Turning the motor upside down.

 

[HighTrim]

Re: Well that tears it! It locked up!

Unless you are looking for a project, I have personally found it cheaper and easier to post a wanted ad in the webvertize of aomci.org for a good used powerhead. Pick it up and bolt her on. Done.

 

[Gas Giant]

Re: Well that tears it! It locked up!

I'll probably wait to order anything until I've torn it all the way down. I'll try the 50/50 ATF and acetone mixture. Heck, it might even work on my Chevy straight 6 that I've had lying on my garage floor since 2005

However, I will try the want ad thing also, you never know.

 

[Gas Giant]

Re: Well that tears it! It locked up!

Ok, got some photos for you guys.

 

[Gas Giant]

Re: Well that tears it! It locked up!

Some more:







I stopped here for tonight, so I haven't gotten to the bearings or anything yet. To me, it looks like the problem came from the exhaust side; to my unprofessional, untrained eyes the head and head gasket don't show any obvious signs of failure.....but maybe you experts out there will see things I don't in my bad photos.

 

[1946Zephyr]

Re: Well that tears it! It locked up!

Well, I would clean it up what you can and get it free. You might be able to save it. These are pretty tough old motors. There's a good chance that the water didn't get past the pistons. Once you break it free, then dump a bunch of fuel mix into the carb and flush out the entire crank case. I think you can revive it. You better. I have one of these too.

 

[HighTrim]

Re: Well that tears it! It locked up!

Wont know for sure until you open her up.

 

[64osby]

Re: Well that tears it! It locked up!

I was confused about how an engine would lock up with only 2 months of sitting. It was covered up.

GG - You say it sat for 2 months. Was this motor in use or were you working on it prior to finishing the repair? I'm just wondering how it could freeze up so quick? Are you in salt water?

 

[samo_ott]

Re: Well that tears it! It locked up!

Did it sit on it's side or upside down?

 

[Gas Giant]

Re: Well that tears it! It locked up!

64osby - I've actually never used it in water, save the barrel of hose water I ran it in for that short moment that it ran. (It has fuel delivery problems.) I've been working on it since August, but when I got the engine then, and up until that 2 months ago, I could spin the flywheel by hand. Now there may have been rust in that cylinder before, I don't know, but it didn't stop the piston. Yeah, I never would have guessed 2 months was enough to freeze up an engine - I had a Trans Am once that sat for 5 years and fired right up after a carb rebuild and fresh gas.

As far as the history of the motor before I got it, it had been sitting a very long time (twenty years or so) but it had only been used on a freshwater lake since new. But, who knows for sure.

samo_ott, the entire time I've owned it, since August, its been sitting upright on the back of my boat. But prior to that, who knows for sure.

I'll tear it down further and post pics as well. Hopefully today.

 

[Chinewalker]

Re: Well that tears it! It locked up!

Might you have used ether to start it that first time? It can remove oil residue from inside the motor and draw in moisture from the air...

 

[F_R]

Re: Well that tears it! It locked up!

The exhaust cover baffle plate looks pretty good in the picture, but I gotta ask---is it aluminum or stainless steel? If aluminum, check that sucker very closley for pin-holes. That will certainly do it. Otherwise, everything looks pretty good. Except for the damage that is.

 

[Gas Giant]

Re: Well that tears it! It locked up!

Chinewalker - I used the same mixed fuel from my tank in a spray bottle and sprayed that down the carb. I went through a whole thing where it would sputter, etc, but after I got it to fire up and run, it didn't need the spray bottle to start up anymore. Even if it would only run until it sucked all the fuel out of the carb..

F_R - I'll take a close look at the exhaust cover baffle plate - I don't remember offhand the material its made of.

Here are some more pics, for those that are interested:





I had to stop for the moment because I'm probably going to bend my Allen wrench into an unrecognizable shape trying to get the rod bolts out, so I need to run down to the store and pick up one of those Allen bits that fits on your breaker bar.

 

[HighTrim]

Re: Well that tears it! It locked up!

Definate rust in there, good thing you opened her up. Clean her up, replace the bearings seals and you will be good to go!