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1955 QD-16 Johnson Help

A

Atlaszmh

Member
Hey guys,

So I just got lucky on Craigslist with an old 1955 Johnson 10hp QD-16.

I have been able to get it started and it runs fine at low-medium thru high RPMs, but when I try to turn the throttle all the way down, it dies.

Along with this statement, I don't see any sort of kill-switch anywhere on the thing and it's impossible to find any manuals online that don't cost an arm and a leg.

So my question is - Is there a kill-switch normally, or do you turn it off by just turning the throttle all the way down?(This seems weird to me, but I am by no means an expert here)

Other than that, the motor seems to run fine for sitting for 8 months and I plan on taking it out on the water sometime this week!

Thanks a lot in advance!

-Zach
 
I believe the metal label on the twist grip has several printed positions including Fast, slow, shift, start and stop.
 
bobbyc just hit the nail on the head, my 1954 Johnson QD-15 has the same outline on the tiller. Love that motor, will run all day and just purrs!
 
OMCNUT said:
bobbyc just hit the nail on the head, my 1954 Johnson QD-15 has the same outline on the tiller. Love that motor, will run all day and just purrs!
Click to expand...

Haha that's typical.. my tiller arm is all worn down with no markings left.

Well thanks for clearing that up!

I took it out on the water for the first time today and unfortunately had a bit of a failure. :(

It runs alright, but only for 15-30 seconds. After that it starts surging and revving high just before dying. It sat for 8 months before I got it, so I am thinking a carb cleaning is probably a safe first step.

The problem I'm having now is - How do I find a carb kit that will work on this motor? I am afraid to buy anything too new because it won't fit, but I can't seem to find any place online with older carb rebuild kits!

Where have you guys had luck with this?

Thanks!

-Zach
 
You are at the right place. marinengine has them. Sierra 18-7043. However, while it is possible you might have a carburetor problem, most likely it is something else. The symptoms say that you are consuming fuel faster than it is being supplied to the carburetor. Highly suspect would be the filter element in the glass bowl on the bottom of the carburetor. If it is partially clogged, it will cause exactly the symptoms you just described. Try running it with the filter temporarily removed. If it runs ok now, well there ya go..

However, the trouble can also be the fuel tank or tank pressurizing system. Does air pressure build up in the tank as it runs? (It should).
 
I agree with the clogged filter diagnosis. I believe the filter is made of sintered bronze...removing it and soaking it in carburetor cleaner should do the trick. Another common problem may be a leaking air hose on the pressure tank or a gas cap which has not been tightened. If it is a tank problem, pumping the primer when the problem occurs will temporarily alleviate the problem.
 
There are a couple upgrades you can do. Adding a single line fuel tank and fuel pump is probably the most common for those old motors. Just get a three port briggs and stratton pump and adapt the intake manifold to a pulse port. The kill switch is easy also and makes restarts easier you add two wires one from each set of points to a kill switch. Just drill a hole in the armature plate and put a grommet in the hole for the two wires. I would just get new OEM points and condensers and do a good tuneup the aftermarket points are crap make sure the box has BRP on it.
 
bobbyc said:
I agree with the clogged filter diagnosis. I believe the filter is made of sintered bronze...removing it and soaking it in carburetor cleaner should do the trick. Another common problem may be a leaking air hose on the pressure tank or a gas cap which has not been tightened. If it is a tank problem, pumping the primer when the problem occurs will temporarily alleviate the problem.
Click to expand...

I do not believe it's an air leak issue to the tank. The tank pressurizes well and I actually already replaced the small air line from the engine to the fuel port as it was cracking and leaking.

I will start with the fuel filter and see how it works after that's been confirmed clean. I was thinking about converting it to a single hose fuel line. Are there any benefits to this besides it being a more modern solution?

If the problem persists, I'll grab that carb kit and see about cleaning it all out. I unscrewed the high speed(lower) lever a ways and noticed the threads looked a bit gunky on there.

Also to note, when I first got it on the water, it ran fine for a few minutes straight. Then, each time I got it started after that, it would run for a smaller and smaller amount of time until I just gave up. Not sure if that is 100% helpful, but I thought I should mention it.

I will report back with my findings!

Thanks,

-Zach
 
If the pressure tank and hoses are in good condition, I see no reason to convert to the single hose system. Unless you decide to open the pressure tank cap while smoking a cigarette, the system will work quite well. Part of the "magic" of these old motors is their originality. It's like adding power windows to your model A Ford...you really don't need to.
 
bobbyc said:
If the pressure tank and hoses are in good condition, I see no reason to convert to the single hose system. Unless you decide to open the pressure tank cap while smoking a cigarette, the system will work quite well. Part of the "magic" of these old motors is their originality. It's like adding power windows to your model A Ford...you really don't need to.
Click to expand...

That's kinda what I was thinking, too.

I am hoping to have some time tomorrow to dig into this again. :)

Thanks again for all your guys' help!

-Zach
 
So I poked at this today and made some headway!

Unfortunately I also found some stuff I could not fix.

Getting the carb bowl off was easy, and I ended up having to take the carb off the rest of the motor to get the actual filter out.

Here's what I found:

yK8micR.jpg


Mmmmm... definitely the culprit of the choking engine.

I sprayed down into the carb with some carb cleaner and let the bits soak in it, too.

When trying to put everything back together, I learned that the carb bowl had a crack and the gasket is shot.

Rvd6pWh.jpg


dcHsi9B.jpg


So now I have a clean filter, but no gasket and a cracked carb bowl!

I've been looking around for the glass carb bowl and that gasket, but it doesn't look like the carb kits here come with them?

Anyone know if these are still available?

Thanks!

-Zach
 
Did you examine the interior of the tank....the dirt in the filter had to come from somewhere and it will get clogged again unless you make sure the tank and hoses are clean. The carb kit should include the bowl gasket but not the bowl itself. If you put some dimensions on the glass bowl, it's possible someone might have one. Be careful with the carb cleaner...it is meant for metal parts only. It can melt rubber and plastic. Because the parts for these motors are hard to find, most people who own them purchase a "parts motor" just in case.
 
Just noticed the pictures show there is a nut missing from the top of the recoil starter. The recoil could eventually fall apart if you don't replace it.
 
bobbyc said:
Did you examine the interior of the tank....the dirt in the filter had to come from somewhere and it will get clogged again unless you make sure the tank and hoses are clean. The carb kit should include the bowl gasket but not the bowl itself. If you put some dimensions on the glass bowl, it's possible someone might have one. Be careful with the carb cleaner...it is meant for metal parts only. It can melt rubber and plastic. Because the parts for these motors are hard to find, most people who own them purchase a "parts motor" just in case.
Click to expand...

Hmm... should be interesting to find a new bowl, then... Although it looks like this same carb was used from 1954 thru 1963?

That adds a little leeway to find this thing. :)

And good catch on the nut! I hadn't even known anything was supposed to be there.

As for the gunk - I don't think the tank is too bad.. This thing was sitting for at least 8 months, and probably much longer since the filter itself was closed. It looked like old/rotten 2-stroke fuel IMO. I will do a double check next time I fill it for sure though.

Thanks again! I will let you all know how this goes.

-Zach
 
bobbyc said:
Just noticed the pictures show there is a nut missing from the top of the recoil starter. The recoil could eventually fall apart if you don't replace it.
Click to expand...

It actually doesn't leak, so I'll move forward with putting this all back together/running it, but I would like to have a non-cracked one in there eventually.

You can't see it from the pic, but the crack doesn't reach either side of the glass. Somehow it's entirely within the glass... at least from what I can tell!
 
Update!

I got the carb kit, but it did not have the fuel bowl gasket. I went down to the plumbing section at the local hardware store and bought some gaskets with the proper inner diameter. unfortunately it did not have the right outer diameter, so I had to snip some away with scissors.

The glass bowl with the crack is holding up well and it doesn't seem to be leaking.

The rest of the carb clean was straightforward.. I didn't pick it apart 100% as it was very clean already(mostly).

I stuck it in a bucket and ran it for a good 5-10 minutes with no issues, so I am thinking it may be good to go!

Probably gonna run it out to the lake tomorrow for another test.

Thanks again for all your help! If anyone knows where to get properly fitted fuel bowl gaskets for these things, that'd be great. haha

Take care,

-Zach
 
What gas/oil ratio are you using??? Auto Parts stores sell gasket material in a wide range of thicknesses should you need it.
 
Atlaszmh said:
Update!

I got the carb kit, but it did not have the fuel bowl gasket. I went down to the plumbing section at the local hardware store and bought some gaskets with the proper inner diameter. unfortunately it did not have the right outer diameter, so I had to snip some away with scissors.

The glass bowl with the crack is holding up well and it doesn't seem to be leaking.

The rest of the carb clean was straightforward.. I didn't pick it apart 100% as it was very clean already(mostly).

I stuck it in a bucket and ran it for a good 5-10 minutes with no issues, so I am thinking it may be good to go!

Probably gonna run it out to the lake tomorrow for another test.

Thanks again for all your help! If anyone knows where to get properly fitted fuel bowl gaskets for these things, that'd be great. haha

Take care,

-Zach
Click to expand...

Proper gasket is part number 303122 right here at marineengine.com
 
bobbyc said:
What gas/oil ratio are you using??? Auto Parts stores sell gasket material in a wide range of thicknesses should you need it.
Click to expand...

I have about 50:1 in there right now. I was reading that a higher ratio is better for the older 2 strokes.

I did see that gasket material.. I was gonna break down and exacto a ring out of it if needed. 8 bucks is pretty steep for a little rubber gasket, but good to know it's available easy enough!

Will report back how she runs in the evening!

-Zach
 
Atlaszmh said:
I have about 50:1 in there right now. I was reading that a higher ratio is better for the older 2 strokes.

I did see that gasket material.. I was gonna break down and exacto a ring out of it if needed. 8 bucks is pretty steep for a little rubber gasket, but good to know it's available easy enough!

Will report back how she runs in the evening!

-Zach
Click to expand...

Report!

Good and bad news..

Good news - The engine ran fine and did not die!(Unless I messed with the knobs too much...)

Bad news - Something is wrong in the gearbox(I'm assuming) At the end of the run, the engine started slipping and then lost all power and revved like crazy. When turning the throttle down, the gears caught again and started powering the prop again, but I couldn't turn it up without the drive slipping and losing power. So that will be fun... any ideas you guys have would be greatly appreciated.

More bad news - The L bracket that attached the transom to the bottom of the boat for reinforcement is tearing... it's an old aluminum boat and I can't even find any parts for it.. so that'll probably have to be a completely custom repair job.. which to me is a bit overwhelming!

So now I'm to the drawing board for that repair, and I need to take apart the motor again to see what's wrong...

Anyway, I will keep checking this thread!

Thanks for all your help thus far!

-Zach
 
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