1957 Johnson 7.5 AD-11 starting restoration

[chri0891]

I tracked down and bought my grandfather's '57 7.5hp seahorse! I'm digging in with hopes it can be brought back to life. First time working on an outboard and I've read 50+ good posts on this site, yet questions are piling up. Probably deserves multiple posts (?) but here's where I'm at. All suggestions welcome.

Overall condition seems ok. Probably stored in unheated garage for 30 years, and not run in the past 20, but freeze plug isn't popped out and it looks clean under the case.

I checked compression (dry) after pulling plugs and squirting in some WD-40. Both cylinders around 60-65psi. I know that's low but hoping it may rebound with Seafoam if it got back running.

Spark in upper cylinder only. I pulled coils and found that flywheel appears to have chewed off the insulation on each primary wire. Despite that, the ohm readings across primary and secondary wires all read around 4.3. I taped over the exposed wire and reinstalled but still no spark. Checked spark plug wires for continuity and the lower cylinder wire is definitely broken somewhere.

The lower unit is not original. My dad seems to recall that it was damaged in the 60s and grandpa replaced it with one off a different motor. Any way to identify these? I couldn't find numbers on the case, but it seems to fit up fine. Color is either white, or has a hint of light green - either way not the red that came with '57s. I know impeller and seal kit is recommended.

I pulled apart the carb and threw it back together with a rebuild kit. It had been rebuilt previously and the head on one of the needle jets was dicey, but I think it reassembled ok.

I also rebuilt the pressure gas tank seals and replaced the fuel hose. The o-rings in the fuel connector are rotted and spit gas under pressure, so I have replacement o-rings but no special tools. So far 'easy diy' youtube has been unhelpful - it's like those guys make the repair before making the video, so their parts pop apart so easy, ha. I'm considering soaking the whole connector in carb cleaner for a couple days to soften the o-ring for picking it out (I know bad idea), since all other pieces and springs seem to be metal...

Finally, the pull start. First, it doesn't grab well, whether you ease into the pull or give it a few quick tugs. I've checked the pawl and it's keeper spring and it's not greased, seems stiff. Any ideas? Second, a full pull only spins the flywheel 2 1/4 times…worn out recoil spring? Or someone didn't wind it up right?

So now what? I think the motor has enough promise and sentimental value to invest my time and money. I see tune-up kits available online at maxrules, individual parts at marineengine. Tempted to go all-in, but I'm not terribly amazing with mechanics and experience with old mowers says that old seals and parts sometimes work best until they're tampered with.

Grandpa was not a wealthy guy but he loved fishing like nothing else and that's something I sure inherited. Would love the chance to get this back on the water… Thanks for your advice!
-Brent

 

[F_R]

Those coils......are you sure? Aren't they cracked? Almost all of them are unless they have already been replaced, and you seem to be saying it hasn't been touched in years If they are cracked or brittle, you are wasting your time until you replace them. Other than that remove and degrease the points and polish each contact individually and reassemble and set gap to 0.020" at their widest opening. Be sure to torque the flywheel nut to 40-45 ft/lbs

Recoil spring has nothing to do with how many times it turns the motor over, unless it is wound too tight. 2+ turns sounds about right to me.

 

[Crosbyman]

if you hope to revive it you have a head start ..it is not locked up and rusted solid. hopefully the innards aren't to bad either

yes pressure is low but...it may come up later with a some use and some decarb product



did you pull the flywheel yet inspect the coil (cracked ???) with things apart change all the plug wires with metallic 7mm wire (no automotive carbon wire)

clean and adj. the points to 0.020

work at it till you get good sparks (5/16 in open air) on both plugs

then… pull the head and change the impeller (replace with proper base gasket if you break it )
check the gearcase later on for water infiltration reaseal if required

lots of videos on utube and folks to help you along

great project great motor here are few utubes to keep you busy

Cheap outboards is a great book
https://www.amazon.ca/Cheap-Outboard.../dp/1891369628
http://www.youtube.com/watch?v=SVOedhzPP7M
http://www.youtube.com/watch?v=EY2HrEdp5vg
https://www.youtube.com/watch?v=GCkpGD4bgDI
https://bit.ly/2wqMPTb this is the bible for all you need to know pretty much
http://www.pochefamily.org/outboard/Coils.htm
http://www.youtube.com/watch?v=ga1Cj...ature=youtu.be

 

[Crosbyman]

cracked coils you can expect

 

[TN-25]

That replacement "foot" on your lower unit could have come from many motors, as that foot was shared by many throughout the years. There's the 5½, 6 & 7½, 1958-on 10, 9½ 1964-73 (hook eliminated after 67). Now the guts may be different as some used a shock absorber on the drive shaft, some used a splined hub on the prop shaft. The 6 used the shock absorber in '65 then switched in '66 to the splined hub.

I have an AD-12 (1958 7½). Those are bronze-bushed motors and as such demand adequate oil in the fuel.They must be good motors as people still run them 60 years later. Just make sure the impeller is fresh & never run it dry out of the water, even for a few seconds. Make sure the head gasket is good & the head is true. Also make sure the exhaust bypass cover isn't leaking since you do not water getting into the crankcase. Good luck finding the plastic emblem for the front. They had reproduced them clear & unplated, or there are silicone decals that are 3-D enough to look good. It took me a while to find an original unbroken '58 emblem with the 3 screw mounting (57s are 2 screw).

 

[chri0891]

Hmm…no coils are not cracked, and they also aren't red like yours crosby. Some parts are so clean I have to believe the previous owner did work on it, though he claimed he just ran it a few years in the late '90s and then set it aside.
Second photo shows the primary a bit better, screwdriver points to where coating is worn through to the wire.
-Brent

 

[Crosbyman]

ok take a reading of the ohms from the spring in the plug boots to engine frame and indicate results you get (should be 4-8 Khoms depending on coil manuf.) )

some plug wires eventually break in the bend under the mag plate and the pin prick in the boot oxidizes

see pictures

you can repair chaffed wires with heat shrink tubing...just tuck them away from moving parts

hard to see… in the pict .....are you missing the cam oiler felt pad ??

 

[Crosbyman]

oil pad wick

 

[lindy46]

Coils have been replaced but condensers look original. I'd replace those and clean up the points if not burned too bad. They may be original too. And I'd replace the plug wires. That should get it sparking.

 

[racerone]

Where the wire coating is worn through is a ground wire.----Just cover it again.

 

[chri0891]

I wasn't able to get any reading between plug boot spring and frame. So I went through the following steps:
1) pulled the coil off, and took a reading between the spike that goes into the plug wire and the primary/secondary leads. Both read 4.25 kohm. I checked the other coil and that's 4.25 all around too. I'll recoat the damaged wires with heat shrink tubing.

2) used the continuity buzzer to try to get a beep from one end of the plug wire to the other. Nothing.
3) pulled the mounting plate off and fished the plug wire out from underneath. Cut an inch off the end that connects to the coil in case it was corroded. Stuck the coil back onto the wire and took a reading from boot spring to primary coil lead. I REALLY had to jam the probe around in the plug boot but finally got a reading: 4.16 kohm.

I think new plug wires, condensers, and points are going on the shopping list. As for the oiler wick, I'm not seeing anything resembling one, or its clip. Should the clip be fastened into one of the mounting screws for the points or coil?

-Brent

 

[chri0891]

Ah-- found how the oiler wick mounts on a different post. And that Johnson service manual link crosby posted?- my head almost exploded! I had been getting all my info from a high school small engine repair textbook.

What I couldn't find is how removing the wick (which apparently happened last time coils were replaced) can damage the cam, which I read in a post. A different post said purpose of the wick "is to lightly lubricate the outside riding surface of the cam so the point shoes do not prematurely wear." In either case I'll try to find a new clip and wick.

 

[racerone]

They are proud of that clip.------But most " old time " shops would have those laying around.

 

[Crosbyman]

that silly little clip is very expensive ..ask around maybe somebody will feel your pain and send you one as a freebie from a parts motor (happened to me )

try the folks on the AOMCI board (being a member can be a plus) the felt comes with new point kits but you can cut one up from those sticky furniture felt pads (felt side on the cam….)

glad you liked that Bible… you can print of groups of pages to your PC into PDF files which you can print off for a maintenance binder on all the oldies you will start collecting (you have been infected) :lol:

 

[chri0891]

Everything is back together with new points, condensers and plug wires. The local marine shop where I got parts found me an oiler clip and only wanted $36 for it! - so instead I fashioned a piece of gutter tin to hold the wick where it seemed to make sense…not a perfect solution but with any luck if the wick does slip out of the crimped tin, it won't cause any major damage.

Best part is I've now got spark @ 5/16", both cylinders! Thanks for the help-
-Brent

 

[Crosbyman]

Contact Tim's outboard for that felt clip … they ell used parts and that clip may be on hand.
http://www.timsoutboard.com/

 

[chri0891]

Will do! Thanks for the reference, hadn't seen that shop yet-