1956 AD-10 Johnson 7.5hp

[MarvK]

Well, I couldn't resist and bought a 1956 Johnson 7.5hp and paid waaaayy to much for it. It's the nicest looking one I've come across in the last several months. Owner had it for 6 years, but said he never started it. He had it in his collection and it was time to start selling off some.

Pulled it over and it has good compression and a good spark on both plugs. Put new J6C plugs in it and changed the oil in the lower unit. Pressure tank checked out and is very clean, not even a hint of rust.

Primed it and it took about a dozen pulls, but it finally started up. It ran for less than a minute and quit. When I tried to restart it, the recoil rope locked solid when I pulled it. Took the cover off and noticed that the flywheel and advance plate were locked as one. Also, when I pull the rope the throttle grip moves with it.

So, only thing I can think of is the coil/magnets were not tight and wedged into the flywheel. Took the inspection cover off, and it looks like the coils were replaced at some point because they don't look original.

Anyone have an idea what else it could be?

Thanks,
Marv

 

[Joe Reeves]

Re: 1956 AD-10 Johnson 7.5hp

Check the coil alignment as follows.

(Magneto & Driver Coil Alignment)
(J. Reeves)

To align the coils properly, have the metal vertical portion of the coil yokes aligned with the inside edge of the bevel that exists on the top portion of the aluminum seat upon which the coils sit. This creates the proper distance between the coils and the flywheel magnets. Faulty alignment creates friction and the yokes of the coils heat up, turn blue and expand.

 

[HighTrim]

Re: 1956 AD-10 Johnson 7.5hp

Pop the flywheel to find out for sure.

 

[MarvK]

Re: 1956 AD-10 Johnson 7.5hp

I plan on pulling it as soon as I have access to a puller in a few days.

I'm sure I'll have more questions then.

Thanks,
Marv

 

[kfa4303]

Re: 1956 AD-10 Johnson 7.5hp

Make sure you use GRADE 8 bolts and washers with the puller. The bolts they come with usually aren't strong enough.

 

[MarvK]

Re: 1956 AD-10 Johnson 7.5hp

Yes, will do. I just hope the coils don't rip off and cause me more headaches.

Wife wasn't real happy when it wouldn't restart. "How much more is this going to cost?" :facepalm:

If I can get it to run as good as it looks, I'll be a happy camper!

Here's a pic of it;

 

[kfa4303]

Re: 1956 AD-10 Johnson 7.5hp

Wow! That's a pretty little motor. Not to worry, you can usually replace/rebuild the carb, ignition, and cooling system on these old motors for less than $100. Best of all you can get everything you need right here at iboats. Coils, carb kits and impellers are only about $20 each. Here's a handy link. It's for a slightly different model, but all of the steps are the same for your motor.


5.5 HP Evinrude Johnson Outboard Tune-Up Procedure 1954-1964

 

[MarvK]

Re: 1956 AD-10 Johnson 7.5hp

***Update***

Pulled off the flywheel last night and it was as I expected. One of the coils was loose and wedged into the magnet. Scored it up some, but I filed and emery sanded it smooth again. The other coil wasn't set properly either. Did as Joe said, and re-aligned it. I hope it doesn't effect the performance of the ignition.

Ran out of time to test it out, will do that tonight and report back.

Marv

 

[MarvK]

Re: 1956 AD-10 Johnson 7.5hp

So I put it in the barrel tonight and got her running. Both the high and low speed needles seemed to be way off. I ended up with the high speed needle turned out about half a turn from being seated. The low speed about 3/4 from being seated. Can't wait to get it out on the water this weekend.

The only other problem I might see is when I pulled it out of the barrel, I noticed a little oil draining out of the drain hole underneath the impeller housing. Am I right in assuming there is a seal below the impeller and above the lower unit? I did replace the oil, but didn't notice any water in it. But then again, the previous owner said he never had it running in the six years he owned it.

Marv

 

[kfa4303]

Re: 1956 AD-10 Johnson 7.5hp

Don't worry about the yuky water in the test tank or the oil drainage on the motor, both are perfectly normal and will go away on the open water. You can also dial in the carb once you hit the lake too. Here's a handy link for getting dialed in just right along with some vids of other 7.5s in action.

http://forums.iboats.com/engine-fre...sorted-carb-variations-joe-reeves-167352.html

1958 Johnson 7.5hp outboard motor - YouTube
1956 Johnson 7.5hp outboard motor - YouTube
1956 Johnson AD-10 7.5hp outboard motor - YouTube

 

[64osby]

Re: 1956 AD-10 Johnson 7.5hp

Marv, Great looking motor. Fine tuning on the water is easy, mine seem to like the idle richer.

You said you paid too much, what does a new motor cost these days?

 

[MarvK]

Re: 1956 AD-10 Johnson 7.5hp

Kfa4303, That would make sense about the oil draining out, water was looking pretty bad and had a lot of oil in it.

And the video links, I think I've seen most all of Ben's outboard videos. I think I heard him say in one video that he had over 200 motors!

64osby, I'm looking forward to tuning the jets on the open water. Does it matter doing the high speed first, then the low speed?

WOT lean till it loses power, then richen till it sputters and back in between those spots, correct?

You are right about the cost of a new one. $425 for this one plus the tank and stand. I see some guys getting one for maybe $150-$200. Depends on the market demand in our areas I guess. I did talk him down $100 from his asking price though. But I have a thing for redheads. :lol:

Thanks guys,
Marv

 

[Joe Reeves]

Re: 1956 AD-10 Johnson 7.5hp

(Carburetor Adjustments - Two Adjustable N/Vs)
(J. Reeves)

Initial settings are: Bottom high speed = seat gently, then open 1 turn out. Top slow speed = seat gently, then open 1-1/2 turns.

Setting the high and low needle valves properly:

NOTE: For engines that DO NOT have a shift selection, obviously there is no NEUTRAL position. Simply lower the rpms to the lowest setting to obtain the low speed needle valve adjustment.

(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn, waiting for the engine to respond between turns, start turning in the bottom high speed needle valve. You'll reach a point whereas the engine will either start to die out or spit back (sounds like a mild backfire). At that point, back out the needle valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest setting.

(Low Speed) Slow the engine down to where it just stays running. Shift into neutral. Again in segments of 1/8 turns, start to turn the top needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out or it will spit back. Again, at that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustments, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

 

[64osby]

Re: 1956 AD-10 Johnson 7.5hp

Take the stand and the nice 2 line tank off the price and I'd say you made a reasonable deal for a beautiful motor, basically ready to run.

When you see the real low dollar deals there is always many hours of work that goes into getting it water ready.

Joe R. has the needle adjustments down to a science.

 

[MarvK]

Re: 1956 AD-10 Johnson 7.5hp

Weekend started early. Got her on the water today. Small adjustments and she runs great! .

Couldn't be happier. Slow idle is better than I expected. High speed seems good too. Only extra cost was $4 for a flywheel nut that was stripped. Now all I need to do is keep a little weight in the front of the boat and it will plane out nicely. :joyous:

Marv

 

[kfa4303]

Re: 1956 AD-10 Johnson 7.5hp

Congrats MarvK! Glad she's running right. Try a cinder block and/or bad of playground sand in the bow to help keep the nose down a bit. We'd love some pics of the little ripper in action too.