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1956 Johnson 10 (QD-17)

S

shinola

Contributing Member
On the advice of folks on this board, I found a good clean fresh-water motor as a project instead of a few of the local saltwater motors I had been tinkering with. I found a very clean QD-17 at the local AOMCI swap meet a few weeks back in central FL. I converted to a fuel pump with the help of Timguy and a few posts on this board.

So now, it's all back together, it cranks easy and idles well, but I think it needs some carb adjustments. I don't have the manual for this one yet, so I'm wondering if anyone has the initial position for the needle valves, and maybe some advice for an inexperienced mechanic on the best way to adjust it in a barrel. (still shopping for the boat).

I should probably describe what it does...

From cold, or warmed up, it starts easy in Neutral and the throttle in "start" position. The throttle won't go above "start" position until it's in gear, so it should rev pretty good there. Once warmed up, it was idling very smooth at very low RPM, but still in the start position. When trying to lower the RPM's and move the the "shift" or "slow" position, the motor shuts off. I didn't open up the carb, as it appears to have been recently serviced. I was able to rev the engine in Neutral by hand on the throttle linkage, and it accelerates, but doesn't sound very smooth. Sorry for the amateur hour description.

Looking for advice, and possible start positions for the needles.

thanks.
 
(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.
 
Thanks Joe. I'll have to give that a try later. I did go check the current settings and they were way off. The top valve (low speed) was a full 3 turns out, and the bottom (high speed) was only 1/2 turn. I reset them to the spec's above and I'll have to give it another try this week. I suppose the best way to set the high speed valve is in operation on a boat and not in a barrel. Still working on getting a boat....

Gator, I don't know exactly how to check the coils if you mean electrically. I've read some of the old manuals and I don't have any equipment. I did pull the fly wheel and it all looked brand new. I'll have to see if I can pull up a picture later but the coils have red plastic covers. Not sure if that's an aftermarket. But they're definitely not originals. I suspect it's running on both since it idled nicely, even though it was at a higher throttle setting than it should have been. Is there a simple test procedure?
 
Here is your coils, shinola. I saved a picture. I will say honestly, I have had pretty good luck with these red coils. You have a very sweet motor there.
 

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shinola said:
Thanks Joe. I'll have to give that a try later. I did go check the current settings and they were way off. The top valve (low speed) was a full 3 turns out, and the bottom (high speed) was only 1/2 turn. I reset them to the spec's above and I'll have to give it another try this week. I suppose the best way to set the high speed valve is in operation on a boat and not in a barrel. Still working on getting a boat....

Gator, I don't know exactly how to check the coils if you mean electrically. I've read some of the old manuals and I don't have any equipment. I did pull the fly wheel and it all looked brand new. I'll have to see if I can pull up a picture later but the coils have red plastic covers. Not sure if that's an aftermarket. But they're definitely not originals. I suspect it's running on both since it idled nicely, even though it was at a higher throttle setting than it should have been. Is there a simple test procedure?
Click to expand...

I agree, it is virtually impossible to get it "right" with it in a tank. But you should be able to get it close. ALL 1956 Johnsons have bad coils unless already replaced, which was the reason for suggesting it. But you got lucky on that score. As for running on one cylinder, they will run very nicely on one, just no power. Easiest way to check is remove and ground one spark plug wire and see how it runs. Then do the same, removing the other wire. If it makes no difference with one of them removed, that is the cylinder doing nothing.
 
The "nature of the beast" is a fixed cowling, so as Joe and Gator state, it is hard, if not impossible, to effectively tune in the barrel....because of fumes from rich exhaust entering the carb. It's best tuned on the boat.....or, on these models, open up the access side and tie it safely, then set up a fan to introduce fresh air.
 
The more I think about it, it might be running on 1. I'll do the check later today. It had a lot of unburned oil floating in the barrel after running for a short time. I thought that might have been from the needle valve being too rich, but it makes more sense that one cylinder was not firing.
 
Can you post that video link you sent me? Since it's your production, I'm not authorized to post it, ha! Sounded like running on both cylinders, but I'm gonna review it again.
Just watched it again....it's running on both, in my opinion. You gotta post it and Joe, Gator, Racer, or another tech can see.
 
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The video file is 10.9MB. It's not letting me upload it. I deleted all other attchments from my profile, but I think the limit must be 10MB.
 
It looks like the only valid file extensions for attachments are: bmp doc gif jpe jpeg jpg pdf png txt

No videos.
 
Great job, brother....now if we can get some advice from the experts.....what you think, Joe, Racer, Gator, Pappy? I think it's hitting on both, just running rich. This is a pretty old girl, born same year as me but certainly it could outlast me......probably the best all around fishing outboard ever made.....still almost every part available, new or used. Think a 2020 Yamaha will still be around in 2085? Ha!
 
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After listening to it about a dozen times, I tend to agree with tim. But still, flip the hood off and do some checks to be sure. Removing the hood is simple on that one.

Motor sounds good, I don't hear any wrist pins banging around (a common 10hp malady)
 
Another video of the motor running. This time, with the carb needle valves set at the initial settings per Joe's post above. Much better running. Now the motor runs at higher idle in "start" and I can almost get all the way to "slow" before it shuts off. FAR less unburned oil.

To re-cap. The earlier video and rough running were with the top valve (low speed) was three full turns out causing it to run way too rich and dump unburned oil into the barrel.

https://youtu.be/5NOB6MW0Q8Q

I gotta get a boat for this thing!
 
So that test made me pretty confident that it was running on both cylinders, but just for my education, I performed the test suggested above to try running on each cylinder individually as gator suggested. It does run but it's rough on either cylinder and dumps plenty of unburned oil in the barrel. Also, it won't idle down to "shift" position, it just shuts off immediately when I try to idle down. Since it runs on either, I can rule out the running on a single cylinder for now. Good education from the board as always.
 
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