1964 Johnson 9.5 HP Seized (MQ-10R)

[Fishon72]

Hello:

I have what I believe to be (based on google search) a 1964 9.5 hp Johnson - model MQ-10R. This is going to be my first time really tinkering with an outboard motor.

As of now, the motor seems to be seized...I can’t get the flywheel to move even by turning it with my hands. Where should I start to at least get the flywheel spinning again? I am planning on replacing/cleaning parts as I go but before I start ordering things and diving into the project I’d like to get it unstuck so I at least know it’s going to run.

Thanks in advance!

 

[CedarRiverScooter]

I'd take the lower unit off, to make sure it isn't the problem. You will want to replace impeller anyway.

Then turn motor so spark plugs are up & put penetrating oil in cylinders. I recommend ATF/acetone 50/50, but everyone has their favorite.

It might take several days for the rust to dissolve, so be patient.

 

[GYPSY400]

^^^ what he said
I hope your into this project for the nostalgia rather than a "daily driver"

If its the former, good luck with your project

If its the latter, you may want to consider something 30 or 40 years newer to start with.

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[Fishon72]

Did as you recommended, when I removed the lower unit the prop still would not turn so I guess there’s an issue there in addition to my problem with the flywheel not budging. I used Kroil in the cylinders, it’s the only penetrating oil I had handy. I’ll report back in a couple days...

I noticed when I was taking the lower unit off the screws weren’t very tight, so I’m guessing the previous owner was fiddling around with it and couldn’t get it going.

Unfortunately I was planning on using this as the daily driver at least for this year, I don’t think I’m going to be able to sell the wife on spending the money on something newer. There isn’t much for sale in my area either at the moment, unless I go brand new. She may just be a row boat for the time being if I can’t get this engine to run

As always really appreciate the feedback from this site!

-Jay

 

[GYPSY400]

Try turning the flywheel in a few days to see if the engine itself frees up. You may have to put a socket on it rather than use the pull cord.
If the prop, or driveshaft won't turn once apart from the main engine thats a whole different issue. The gears in the bottom end are seized too.

If neither one frees up easily, I would consider finding a new motor and cut your losses now. These old motors are great for nostalgia, but require constant tinkering with skilled hands and lots of experience (a guy like Pappy). This being your first BBQ may leave a bad taste in your mouth... But yeah I get it, its a bad year to buy toys, and a real hard sell with the wife.

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[Weldorthemagnificent]

Careful using a socket on the flywheel nut. You can strip the thread if cranking too hard on it. As mentioned a lot of different oil combinations but what works is what you have on hand. I just unstuck a 1964 FD-18-E using WD 40 and 2 stroke oil. That and knocking the flywheel back and forth with a hammer and a brass drift (it has a gear on it). Give the oil a chance to work and try knocking it back and forth with a rubber mallet or deadblow hammer. Or
fashion a strap wrench.

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[CedarRiverScooter]

Just another though - On the 18 hp 'rude I bought last year, the flywheel key was 1/2 sheared through. So don't go crazy on it.

 

[old_fart]

Have you opened up the bottom end
to look at the condition of the crank?

If the rod journals are rusted...

-W

 

[Sinkingfast]

That was my first thought. The heck with the top end but the crank and stuff, if rusted, is problematic.

 

[Pappy]

Let him see if the Kroil (which is great stuff) works first. A strap wrench is an excellent way to apply safe high torque to help free an engine. Another way is to take a spark plug apart and install a grease fitting in it and pump the cylinder with grease. The hydraulic pressure will free an engine in a heartbeat.

Secondly - Why would you go to the trouble of dis-assembling the crankcase to see the crank before simply pulling the cylinder head to check the cylinders for rust!! Do not dis-assemble anything major on this before exhausting every possible way of freeing up the engine.
Heck the spark plugs should tell you the condition if water got in as well as checking the fuel supply from the last fuel source the engine ran off of. That can be checked for water in the fuel.

 

[Sinkingfast]

Obviously the checking the crank was not connected to freeing it up in my post. Just don't get lazy and not address the bottom end while you are this far like others might be inclined to do.


Take the extra time to give it some love. It will love back.

 

[Fishon72]

Just an update...I’ve used up all my kroil on this, adding more, letting it soak for a couple days, trying to break it free, and repeat. At this point the flywheel still has zero give to it. There is no play whatsoever in it in either direction; it feels like it’s welded in place. I was able to remove the bolt from the top, which wasn’t on there very tight (almost as if somebody took it off and finger tightened it back on.)
I’ll try the grease trick next and have a strap wrench on order. I’ve also already purchased a pair of oars because it doesn’t look like this motor will be running by spring at this point it’s just going to be a fun project.

I appreciate all the insight! I’ll keep at it and keep you all posted!

-Jay

 

[nccatfisher]

I would consider removing the head and tap on the pistons with a block of wood and a mallet. Don't get carried away. Use more Kroil or the concoction CedarRiver mentioned and keep it turned up where it is standing full enough to keep soaking. Give it a sharp rap and let it set just keep bumping it daily. Do this over a week or ten days. If that didn't work then put the head back on and resort to hydraulic action.

 

[CedarRiverScooter]

Another tactic would be to evaluate the wear components (water pump, coils, carb, starter, fuel pump, lower unit seals) & add up what it will cost to bring the motor back to a reliable operating condition.

If it needs everything, maybe it is a lost cause & should be left a donor motor.

 

[Fishon72]

Been soaking it for a week and a half with the ATF/Acetone mix, tapping it every other day or so. Still zero movement. I’m thinking this one is probably a lost cause...even if I do get it unstuck I can’t imagine it will be a reliable runner afterwards.
Thanks again for all the suggestions!

 

[Weldorthemagnificent]

Tap it harder. What have you got to lose?

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[CedarRiverScooter]

If you have the time & motivation, you could tear it down all the way (split the case). Then you will know exactly what the problem is.