18hp Johnson 1963 white smoke and full choke

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 07 Oct 2019, 08:37

Hello . Wondering if anyone can give me some advice on a recently purchased 1963 18hp Johnson Seahorse (model FD-17M) outboard that’s all of a sudden having a number of issues... hoping that they’re all connected to one thing.

Motor ran great, besides occasional misfires. Idled very nice, makes my 14ft aluminum V hull fly (1967 Crestliner). I’ve used the motor 5 trips now. Ran awesome the first 3. Was difficult to start the 4th, but ran normally after that initial pull party.

Took it out a few days ago (5th trip) and it was PAIN to start. A LOT of squeezing the bulb and full choke before I finally got it going, pulled so many times each time I needed to start it that I’ve got broken blisters between my fingers. It will only run at full choke and die if I push it in at all. Won’t idle nice and low like it would before, have to keep a higher throttle. On my way back to the launch I noticed a lot of white smoke started to show up and so I shut her down. Operated it in short bursts turning it off when the smoke would come again. Motor has a good pee stream still.

I also notice that it stinks the whole garage up with the smell of gas and leaks a little gas onto the floor. Small puddle. It has done this for the month that I’ve owned it.

Had it in a barrel the last two days futzing with it.

I’ve gotten suggestions to check the spark plugs. They look good and have a spark. Ordered a spark tester so I can be sure they’re putting out enough, however, as I was told that even though they have a spark it may not be enough.

I’ve gotten suggestions to check the compression. Ordered a compression tester, so I’m on the path to checking that too to see if I also need to order a new head gasket.

I’ve gotten suggestions to pop the flywheel and check the coils. I’ll order the tools to do that if the spark tests come back weak.

I cleaned the carb, but no change.

Fuel is fairly new. Have two tanks, one came with the motor that has month old gas in it, the second I already had from my previous motor that has 3 month old gas in it. 50:1 mixture in both tanks. The motor has been run using both tanks at different times.

I’m new to a lot of this, as evident by needing to order all of these tools. Just learned how to clean a carburetor last year with another motor I own... which was the extent of my knowledge up to this point (thanks YouTube!).

I was referred to this forum by a member of the Michigan Sportsman’s forum, as an awesome resource of folks that have a passion for old motors... and that you all may have some ideas on what else I may need to try.

Thank you!

Xtremeboats
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Pappy
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18hp Johnson 1963 white smoke and full choke

Post by Pappy » 07 Oct 2019, 09:41

Welcome to the forum!
We will start with the basics, as always, and you are already on the right track with that.
Once you have a compression tester and a spark tester let's see what you have and go from there.
In the mean time and from the sound of it the carb will have to be looked at again.
One thing you did not mention was parts. When you go into the carb have a new OEM kit ready to go. Not aftermarket!!
When you go under the flywheel have a new OEM tune-up kit ready to install.....you get the idea.
Have you checked the gearcase for water in the oil yet? Has nothing to do with your issue but it needs to be done.
You mentioned fuel/oil coming out of the gearcase. Normal. The richer the engine and the longer it idles prior to shut down the more will run out for a couple days.

CedarRiverScooter
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18hp Johnson 1963 white smoke and full choke

Post by CedarRiverScooter » 07 Oct 2019, 19:43

I just got same motor, The float/needle clip was not in place so needle was stuck open. Take another look at it, also check float level.

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 07 Oct 2019, 21:00

Pappy wrote:
07 Oct 2019, 09:41
Welcome to the forum!
We will start with the basics, as always, and you are already on the right track with that.
Once you have a compression tester and a spark tester let's see what you have and go from there.
In the mean time and from the sound of it the carb will have to be looked at again.
One thing you did not mention was parts. When you go into the carb have a new OEM kit ready to go. Not aftermarket!!
When you go under the flywheel have a new OEM tune-up kit ready to install.....you get the idea.
Have you checked the gearcase for water in the oil yet? Has nothing to do with your issue but it needs to be done.
You mentioned fuel/oil coming out of the gearcase. Normal. The richer the engine and the longer it idles prior to shut down the more will run out for a couple days.
Thanks for the warm welcome :)

Just ran my tests.

All compression tests captured 100 psi from both cylinders consistently.

For the spark tests I used an adjustable tool, so I could vary the distance and see how long of a spark could be generated. I heard this was a lot better then some of the light or don’t light ones that may not detect a weak spark, lighting up anyway.

One line can consistently generate a 1cm spark, straight line, which looked bright white to me. I assume this is the bright blue/purple the test indicates as normal... my eyes just can’t detect that subtlety with something that is there and gone that quick while being shaken due to me yanking in the starter.

The other line didn’t so hot. 1/2cm spark was its max, was whitish fading to orangish across the arc. Assuming this is the red that the instructions say means a bad coil.

Sounds like I’m taking off the flywheel?

I also ordered an OEM carb kit. You are correct, I cleaned the carb but did not replace all of the gaskets and junk with new ones. So I should revisit that again just to make sure everything is on the up and up.

When you mention OEM tuneup kit for under the flywheel, what does that include? More than just a new coil?

Thank you!

nccatfisher
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18hp Johnson 1963 white smoke and full choke

Post by nccatfisher » 07 Oct 2019, 21:27

It will be points and condenser X2. Coils would be a separate purchase if needed.

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Pappy
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18hp Johnson 1963 white smoke and full choke

Post by Pappy » 08 Oct 2019, 10:15

Your carb kit will come complete with welch plugs. Those are the small aluminum discs. On the top rear of your carb and lined up with the idle mixture needle you will have one that needs to be removed when you clean the carb this time. To remove it take a 1/8" drill and make a hole in the old one then take a punch and insert it into the plug and pry it out.
***Make sure you use minimal pressure on the drill bit as below the plug there are 3-4 calibrated holes in the throat of the carb that you don't want to tear up with the drill bit.*** Clean the carb with this out and verify the holes are clean and clear.
When replacing just lay the new plug in there and put the carb on a firm surface. I use a small flat drift punch but you can use the end of a 1/4" drive extension to tap it in. Place the extension on the top center of the plug and LIGHTLY tap with a hammer. Takes almost nothing to seat it so be careful.
Under the flywheel just take pictures for reference. Note that all wires are usually tucked in behind or under to keep away from the rotating flywheel.
If you think you need a coil do not buy afternarket!
This should give you enough to work on for a bit. We will cover more about the tuneup kit and what to do under the flywheel next.

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 09 Oct 2019, 22:38

Today to my doorstep arrived:

Flywheel tools
OEM Carb kit
Gear lube and plunger hose attachment

OEM coils come tomorrow
OEM points and condensers are due Saturday

Was pretty disappointed when the motor conked out on me, but I’ve got to say I’m getting pretty excited to tear into it this weekend.

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Pappy
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18hp Johnson 1963 white smoke and full choke

Post by Pappy » 10 Oct 2019, 09:18

It is pretty cool to bring one of the oldies back into reliable service!
If you do searches here you will find tons of threads similar to yours in which it is recommended that you go through the ignition, carb, and gearcase (water pump and probably at least a shift rod seal) prior to spending a lot of time on the water with a half century old engine.
Really nothing more than you would be doing with a similar old car or truck found in a barn somewhere......
Lots of discussion on OEM parts vs aftermarket and the issues we have seen with the latter as well. Glad you got your tools in. Sounds like you have a fun Saturday project ahead!

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 13 Oct 2019, 20:06

Changed the coils, condensers, and points yesterday. Had a nice spark on both after that! Got excited and tried to start it, but nothing.

Today I cleaned the carb fully, replacing all gaskets, the float (even though the old one looked new), needle, welch plug, etc.

Still nothing.

Checked with my spark tester again and I’ve lost spark again on one line. Had to have gone out right away yesterday when I was trying to start it. Paid a lot more to get OEM specifically, only to have something go bad immediately.

Wish I would have written down which line it was that was bad before. I want to say it’s the same line... but need to swap parts around to confirm. Unless there is some “cheap” tester I can get to test each part individually?

Also would like to confirm that there’s isn’t something wrong with the line itself. But I had such a nice spark yesterday.

There was one original coil and one new looking one in there when I first opened it up. Need to confirm when I have more time to play with it again... but at the time I was sure that it was the newer one that has failed... which is the same spot my currently failing one is too.

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Pappy
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18hp Johnson 1963 white smoke and full choke

Post by Pappy » 13 Oct 2019, 21:46

Never assume it was a new part that failed before checking. Pretty rare.
Right off the bat go as narrow as possible with the spark checker and see if you have some spark on both or just hook up a plug to the wire and see.
Lots of things can go wrong with the way the work was done as well. Sorry but true. The coil wire may be arcing at the exit of the new coil or coils or anywhere in between. Wires that you routed when changing out the coils and condensors may have been left a bit too high and caught by the flywheel etc. Go back and check. Did you put on the new oil wick while there? Not your issue but hopefully you replaced while there as it was in the tune up kit.
The engine should have fired on one cylinder anyway so you have not found the issue.
If this engine has a fixed high speed jet did you pull it out of the bowl? If not it could very well be plugged solid. That jet has to flow as it supplies the idle circuit with fuel when that circuit is flowing. You never specified.
Pull the line off the fuel pump that supplies the carb at the carb end. Verify flow with the primer bulb.Hook it back up. Pull the bowl drain loose and verify the bowl is getting fuel.
Make sure the choke blade closes FULLY not just most of the way.
This should give you enough to do for now.

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 13 Oct 2019, 22:55

Pappy wrote:
13 Oct 2019, 21:46
Never assume it was a new part that failed before checking. Pretty rare.
Right off the bat go as narrow as possible with the spark checker and see if you have some spark on both or just hook up a plug to the wire and see.
Lots of things can go wrong with the way the work was done as well. Sorry but true. The coil wire may be arcing at the exit of the new coil or coils or anywhere in between. Wires that you routed when changing out the coils and condensors may have been left a bit too high and caught by the flywheel etc. Go back and check. Did you put on the new oil wick while there? Not your issue but hopefully you replaced while there as it was in the tune up kit.
The engine should have fired on one cylinder anyway so you have not found the issue.
If this engine has a fixed high speed jet did you pull it out of the bowl? If not it could very well be plugged solid. That jet has to flow as it supplies the idle circuit with fuel when that circuit is flowing. You never specified.
Pull the line off the fuel pump that supplies the carb at the carb end. Verify flow with the primer bulb.Hook it back up. Pull the bowl drain loose and verify the bowl is getting fuel.
Make sure the choke blade closes FULLY not just most of the way.
This should give you enough to do for now.
I plan to mess with the electrical again to do more troubleshooting. Wasn’t aware it could fire on one cylinder, so yeah, could be more... though that is kinda discouraging that my perfectly running motor when I bought it suddenly has multiple difficult to find things wrong all at the same time. Makes me wonder if they guy that sold it wasn’t all that forthcoming about its condition.

The engine has both idle and high speed needles. I pulled everything and squirted carb cleaner through and through every orifice. Bowl definitely gets gas when I squeeze the bulb. I can hear it gong in, and have seen it in there both times I’ve taken the carb apart. I’ve found some conflicting documentation on how far to turn the needles out. One place says 1 1/2 turns for the idle needle and 3/4 turn for high speed... another says 3/4 for both needles. I’ve experimented with both... but this doesn’t sound like it would prevent it from running, it would just run rough if not dialed in.

The choke blade definitely does not close all the way. I’ll need to figure out how to adjust that... though this doesn’t look very adjustable, and is what I would call a sloppy mess that resembles a Rube Goldberg device.
Last edited by cosborn on 14 Oct 2019, 10:11, edited 1 time in total.

CedarRiverScooter
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18hp Johnson 1963 white smoke and full choke

Post by CedarRiverScooter » 14 Oct 2019, 08:11

If you have an ohmmeter you could check that the grounding wire at the coil isn't grounded until switch is pushed. On mine, the carb throttle linkage was set wrong, I reset it so that throttle plate was wide open when the stator plate was at the stop (it was a long way from this). With the carb misadjusted, the timing was too advanced & made it hard to start. That wouldn't kill the spark though.

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 14 Oct 2019, 09:45

CedarRiverScooter wrote:
14 Oct 2019, 08:11
If you have an ohmmeter you could check that the grounding wire at the coil isn't grounded until switch is pushed. On mine, the carb throttle linkage was set wrong, I reset it so that throttle plate was wide open when the stator plate was at the stop (it was a long way from this). With the carb misadjusted, the timing was too advanced & made it hard to start. That wouldn't kill the spark though.
Would something like this do the job?

Want to make sure I get the correct thing, one that has the features and range needed, while still remaining on the cheap.

CedarRiverScooter
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18hp Johnson 1963 white smoke and full choke

Post by CedarRiverScooter » 14 Oct 2019, 17:18

Yes that is it. You might want to spend $5 more & get a mid-grade one, as you will use it for many things in the future. The entry level items just don't hold up in my experience.

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 14 Oct 2019, 20:36

Okay... some SUCCESS tonight. She RUNS... but still white smoke (more about that in a sec).



Messed around under the fly wheel again. Double checked the gap on my points, and believe I had the new one I put in too narrow. Also attempted to tuck some cables in better as well, particularly the ground coming from the new coil may have been too close to the drive shaft.

Nice white sparks from both now!

Looked at the choke linkage mess. There is a lever that has fallen and was blocking some of the movement in there. Looks like a little plastic tab used to hold it up that has broken off (circled). This arm would have pulled a little rubber wheel away from the base of the magneto plate. Pushed that arm out of the way for now and the choke plate “almost” closes all the way (the arm scribbled out):
CD611148-77AA-445D-A431-391CCA8DF00B.jpeg

Started her up, little difficult but got it going. Don’t need full choke anymore now either... though I think there is still some adjustments to make to the idle needle.

White smoke did start up again.

In this pic, this is the exhaust, correct? This is where the white smoke is coming from, as well as a bunch of water... which I assume is very bad... new head gasket? Most of the water comes spilling out when the engine stops.
85529E67-9A50-4952-B5BD-8EE79D790214.png
I’ve been meaning to check the thermostat too... will get to that soon too.

There is also a lot of nasty black muck ending up in the water:
08BC78D9-CE6B-425A-9015-0AB3FF986326.jpeg

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