Topic: 1957 FD11 Johnson questions – Antique Outboard Motor Club,Inc

This topic has 12 replies, 6 voices, and was last updated 6 years, 11 months ago by fisherman6.

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May 20, 2017 at 1:43 am #7066
shoestringmariner
Participant
Hey guys, I just dragged home a classic old wooden boat (my brother thinks I’m nuts) and it’s got a nice looking 1957 Johnson FD-11 on it.

I am going to check it over tomorrow and see if I cant get it up and running.

I did notice that the lower pivot point in the lower unit has some slop in it. Is there a bushing in there that wears out, or is some slop here normal? (photos below)

Edit: Question 2 and this is odd to me (not a small engine pro, so bear with me) – I chose this motor out of several due to it feeling like high compression with its wump, wump sounding compression when it was pulled over. His pricing was quite fair and he seemed meticulous about his stuff and collection, so I didn’t check the compression when I was there. When I got it home, I did a comp test and was surprised to find only 60psi.The oddities didn’t end there. The bottom cyl hits 60 and quickly goes to zero. That, and the motor is still tight. Pulling over with both plugs out, its still tight and still acts as if the plugs were in, though with a less "wump wump". Its almost like the plugs were still in. I havent pulled the head as I’m trying to exchange it for another motor that was included in the picks
May 20, 2017 at 3:31 am #58023
Mumbles
Participant
There’s a rubber bushing sort of thing in there Johnson refers to as a shock absorber. It wears out mostly from lack of lubrication allowing the swivel bracket to fill up with water. If you have a replacement part on hand, it can be easily installed by removing the lower mount covers instead of taking everything apart.

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May 20, 2017 at 10:33 am #58034
shoestringmariner
Participant
Thanks Mumbles. I assumed it would be something like that
May 20, 2017 at 10:37 am #58035
fleetwin
Participant
US Member - 2 Years
I don’t think I believe your compression gage….I would try another gage before getting too concerned…
The engine sure looks nice on the outside, but how does it look with the cover off? Does it look like it has been overheated? There is the possibility that the head gasket is blown causing low compression. But again, I would want to confirm these readings with another compression gage before removing the head. You may want to attempt to start the engine first, then recheck compression as well…
May 20, 2017 at 10:53 am #58036
shoestringmariner
Participant
Thanks Fleetwin. I hear what your saying, but why is it so tight with the plugs out? New impeller? I can seriously only pull this motor over two revolutions its that tight.
No signs of overheating. The head has been off at one point (paint off of bolts). I wondered about the gasket, but assumed they go at the thin section between cyls. I didn’t consider it blowing out the side. Are you thinking the rings are stuck?

If I dont hear back from the PO about an exchange, I’ll barrel test it and recheck the comp. I did the comp test twice last night, same results. My tester has worked fine on other motors in the past…my continental welder engine is +/- 150psi across the board, so I know this gauge shows pressure
May 20, 2017 at 11:02 am #58037
jerry-ahrens
Participant
US Member
So you are saying that your compression gauge ”bleeds off”after you stop cranking the motor? if so, the valve core is shot inside the hose end of your tester. I hear tell, that they are not the same as the ones in a tire valve core, just an FYI.
I remember that a few years back, Sierra was making water pump impellers that were too thick… this would cause the motor to ”bind up” while cranking. So bad, that you would have difficulty pulling the motor over with the recoil starter. Maybe you should drop the lower unit, then see how it feels?
May 20, 2017 at 12:03 pm #58042
fisherman6
Participant
US Member - 2 Years
Jerry said exactly what I was going to say concerning the compression gage.

I have heard of the extra thick Sierra impellers causing problems though I have not experienced it myself. Are you getting 2 revolutions or 1 revolution with 2 "thumps" ( one for each cylinder? 2 full revolutions is plenty to start it. If the motor has been sitting for a long time, the oil in the bearings tends to get gummy and makes it hard to pull also. The cylinders get dry and compression numbers can be a bit low. An FD in good condition usually shows over 90psi, sometimes over 100psi on either of my 2 gages. If your gage is bleeding down, I suspect there is an issue with it. I have had plenty of motors come to me that sat idle for many years and pulled over stiffly and after 10 minutes of running feel like new again. Don’t give up on it, its a very nice looking FD and they are great motors. You can pull the bypass covers and check if the rings are free and get a little but of a look at the piston and bores thru the intake ports.
-Ben

OldJohnnyRude on YouTube
May 20, 2017 at 12:26 pm #58044
shoestringmariner
Participant
Thanks guys. I tested it twice with the exact same results. top holds, bottom does not.
I’ll try a 3rd time and see. I’m also going to see if it will run in the barrel. (yes it does two full pops when I pull it) If it runs, I’ll let it run for a few minutes and try it again.

As for the gauge, I’ve used it recently on other motors. no issues. if it was the valve, would it not lose pressure on the top cyl also? Maybe I’ll buy another to try and compare
May 20, 2017 at 12:33 pm #58046
chinewalker
Participant
US Member
Unless something is inside the cylinder and hitting the valve to release the pressure, I say it’s a gauge issue. I suspect you’ll also get higher readings if you pull the lower unit off, releiving any friction from the impeller. I had a 9.5hp low boy that I had installed a Sierra about two years ago. It swelled quite a bit and made the motor very difficult to pull over. Easiest thing to check and inexpensive to replace if needed.
May 21, 2017 at 5:26 pm #58111
shoestringmariner
Participant
Thanks Chinewalker, the seller had agreed to let me exchange it for another, so I can’t take
It apart. He strikes me as a meticulous guy and probably not appreciate me doing that. I’m going to try and run it, then check the comp again. I bought another tester, will check with that if I get the same results as the first test.
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