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 » 14 Oct 2019, 22:24

cosborn wrote:
14 Oct 2019, 20:36
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
Reading up on this I’m seeing conflicting reports. Most places are saying this is normal, with some saying the thermostat is likely stuck open. How much water is too much? The picture shows a stream, but i did see more that this a few times just dump out when the engine turned off. I didn’t keep it running too long because the white smoke worried me, plus the trash can I was using was on the small side so motor would pee the water level dangerously low and I kept having to hose it back up again lol. It also starts backfiring/stuttering on a regular interval and quits when I go any lower than the max idle throttle (guessing I need to open the idle needle up a bit more?).
Last edited by cosborn on 15 Oct 2019, 01:10, edited 2 times in total.

RazorBaits
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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 14 Oct 2019, 22:28


CedarRiverScooter
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18hp Johnson 1963 white smoke and full choke

Post by CedarRiverScooter » 15 Oct 2019, 09:28

Congrats on getting it started again. The muck in the barrel is normal. The nostril you show in picture is not the main exhaust only for pressure relief at idle.

Check that the carb is wide open when stator plate is at the rotation stop. Mine wasn't. Made a huge difference in idle when I fixed that.

The thermostat is easy to pull out. It will be obvious if it is stuck open. If it is closed, you can check that it opens in a hot pan on the stove.

Good luck

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Pappy
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18hp Johnson 1963 white smoke and full choke

Post by Pappy » 15 Oct 2019, 09:41

The water is supposed to come out at that point and lots of it. it is a relief and if you look inside it you will find the small holes the water exits from. Not the total water volume needed for the engine by any means, just a good indicator your pump is working.
Second....your water level in your bucket is wayyyyyy below where it needs to be.
The water level in any tank or bucket should be up around those two lower "Clamshell" pieces above your cavitation plate. The water pumps are not self priming and you are very lucky yours has worked so far.
The thermostat is designed to function at idle only and just off-idle. Engine temp should be up around 135f or so at idle. Hot enough to where you cannot hold your hand on the head for more than 5-6 seconds. OMC thermostats if failed, typically fail in the open position.
Third, and most important!!! In your video I see no water coming out of the relief at idle.......a solid heavy spray should be coming out at all times. What is coming out is solid steam! That is your white smoke. You have probably damaged your impeller at this point trying to run it in that little bucket. Well worth checking. Other than that the engine sounds strong and with adjustments I think you will have a nice engine!

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 15 Oct 2019, 11:22

Pappy wrote:
15 Oct 2019, 09:41
The water is supposed to come out at that point and lots of it. it is a relief and if you look inside it you will find the small holes the water exits from. Not the total water volume needed for the engine by any means, just a good indicator your pump is working.
Second....your water level in your bucket is wayyyyyy below where it needs to be.
The water level in any tank or bucket should be up around those two lower "Clamshell" pieces above your cavitation plate. The water pumps are not self priming and you are very lucky yours has worked so far.
The thermostat is designed to function at idle only and just off-idle. Engine temp should be up around 135f or so at idle. Hot enough to where you cannot hold your hand on the head for more than 5-6 seconds. OMC thermostats if failed, typically fail in the open position.
Third, and most important!!! In your video I see no water coming out of the relief at idle.......a solid heavy spray should be coming out at all times. What is coming out is solid steam! That is your white smoke. You have probably damaged your impeller at this point trying to run it in that little bucket. Well worth checking. Other than that the engine sounds strong and with adjustments I think you will have a nice engine!
The white steam started out on the lake when the engine had a lot more than a tiny bucket. The tiny bucket kinda sucks I know, my big barrel unfortunately cracked when I was messing with my other motor :( I kept watching the motor and once I saw the level get low and the pee stream start to taper off like that I would shut her down and top off the bucket before trying again. I can try to duct tape the hell out of the large bucket and try it again, maybe put something under the bucket to get it up in the air higher... or just take her and some tools out to the lake instead.

So the steam is an indication of an impeller issue, there should be a lot more water coming through that port instead of the steam? Does the impeller also drive the pee stream that comes out near the bottom of the powerhead? Because that seems to be nice strong stream... enough so that it's shooting out past my tiny bucket.
Last edited by cosborn on 15 Oct 2019, 12:13, edited 1 time in total.

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 15 Oct 2019, 11:34

Pappy wrote:
15 Oct 2019, 09:41
Other than that the engine sounds strong and with adjustments I think you will have a nice engine!
I've been looping that video over and over just listening to it, loving the sound. Don't know why other than it just sounds sweet to my ears. I now understand why people constantly rev their motorcycles.

Hopefully I can get it idling nicer lower. That was it at full idle speed, if I let go of the tiller at all it would twist back a touch and start sputtering constantly and wind down to a nothing and stop. When I first got the motor it idled a lot lower and only backfired a little here and there.

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 15 Oct 2019, 11:41

I also have an old Ted Williams Sears 7.5hp motor. I hear those were pieces of crap when they were brand new :) It came with my boat, pretty much as a "I can't even give away this motor, so here you go" inclusion with the purchase of the boat. It's always ran horrible, no low idle at all, full tilt throttle or nothing. Kinda excited to turn my new tools towards this motor now too to see if I can do anything with it.

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 15 Oct 2019, 12:03

CedarRiverScooter wrote:
15 Oct 2019, 09:28
Congrats on getting it started again.
Thank you!
CedarRiverScooter wrote:
15 Oct 2019, 09:28
The muck in the barrel is normal. The nostril you show in picture is not the main exhaust only for pressure relief at idle.

Check that the carb is wide open when stator plate is at the rotation stop. Mine wasn't. Made a huge difference in idle when I fixed that.

The thermostat is easy to pull out. It will be obvious if it is stuck open. If it is closed, you can check that it opens in a hot pan on the stove.

Good luck
Looks like it's wide open when not choked. I read somewhere that the sputtering/backfiring at idle is because it's running too lean, and that I need to close the idle needle a little, but in practice I was noticing the opposite. If I closed the needle anymore than I had it the motor sputtered worse and I couldn't keep it running. When I opened it more (maxing my dial where I currently have it) it stayed running with regular sputters/backfires. I need to take the little dial off again to twist the needle out a little more to give the dial a little more range.

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Pappy
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18hp Johnson 1963 white smoke and full choke

Post by Pappy » 15 Oct 2019, 19:38

Your idle needle controls the fuel/air emulsion. You are correct in how it works. In will close of the emulsion and lean the engine and out will richen it.
When in the water and doing your final adjustments you will want to lean the needle to the point the engine spits lean and then back the needle out 1/8-1/4 turn for best idle. Make your adjustments slowly and listen to the engine. As you are finding out, it will tell you what it wants.
High speed needle should start a bit on the rich side and then at WOT you lean it to the highest RPM and keep going until you hear the engine slow a bit. Bring the needle back out to the highest RPM and richen another 1/8 turn or so.
There should be an idle throttle stop that is adjustable on that engine down at the gear on the port side under the pan. You can use it to set minimum idle RPM

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 17 Oct 2019, 21:44

Finally had time to mess with the idle needle in the garage, but not enough time to take her out to the lake until the weekend.

Much nicer, low idle, no backfiring, no sputtering out. Started on the second pull cold. First pull after that, no choke. Running better than when I got her (was a touch of backfiring when I bought it).

Propped the bucket up a little higher and let the hose run enough to counter the loss exiting the bucket. Definitely seeing a strong stream and a lot less steam. But is that enough water coming out the back port?

https://www.dropbox.com/s/qdpdjndy8hdsr ... M.mov?dl=0

Won’t know if I get more till I can open her up on the lake, and if the white steam is completely gone now. Possible that I was getting it while on the lake before because of the choke needing to be out all the time to keep her running (overheating resulting in the extra steam?).

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18hp Johnson 1963 white smoke and full choke

Post by nccatfisher » 17 Oct 2019, 22:54

Pappy will most likely chime in but it sounds pretty good for running in a barrel. You seem pretty intent on getting the idle "lower" you will have to finally adjust it when you have it in the water due to pressure. I would say just by ear you may wind up having to go a shade higher with your idle, but you won't know that to you actually water test it. I think with pressure and when you put it in gear you will find it may be a bit low even with tweaking your air/fuel setting.

Those motors would idle pretty good for a two cycle when they were properly tuned.

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Pappy
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18hp Johnson 1963 white smoke and full choke

Post by Pappy » 18 Oct 2019, 19:19

Choke being out in order to run has zero to do with an overheat.
Looked at the video. A previous owner has added an overboard indicator hose to the engine. From the looks of it the normal water exit has a bit of a reduction of flow but the overboard indicator stream is nice and strong.
Steam.....remember that in cooler water you will always have steam. Even down here in warm water I get it after an on-plane run. Super hot exhaust gases and inner exhaust surfaces that the cooling water is flowing across to remove heat from the parts. That creates steam!

The engine sounds super! Well done and no doubt a good learning experience! Why not add your location to your signature so we can see where you are boating?
If you like the old engines there are antique outboard (vintage too) groups that hold regular events all across the country. Engines are usually for sale at them all the time.

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cosborn
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18hp Johnson 1963 white smoke and full choke

Post by cosborn » 19 Oct 2019, 11:50

Pappy wrote:
18 Oct 2019, 19:19
Choke being out in order to run has zero to do with an overheat.
Looked at the video. A previous owner has added an overboard indicator hose to the engine. From the looks of it the normal water exit has a bit of a reduction of flow but the overboard indicator stream is nice and strong.
Steam.....remember that in cooler water you will always have steam. Even down here in warm water I get it after an on-plane run. Super hot exhaust gases and inner exhaust surfaces that the cooling water is flowing across to remove heat from the parts. That creates steam!

The engine sounds super! Well done and no doubt a good learning experience! Why not add your location to your signature so we can see where you are boating?
If you like the old engines there are antique outboard (vintage too) groups that hold regular events all across the country. Engines are usually for sale at them all the time.
I’ll update my profile... I’m in Grand Rapids, MI.

Interesting... so that pee stream is not original to the motor?

Thank you all for your advice! I’ve learned a ton. This was a fun project and super satisfying to have it running so strong now. Will get to take it out to a lake tomorrow morning to do some fishing and finally adjust the high speed needle.

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Pappy
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18hp Johnson 1963 white smoke and full choke

Post by Pappy » 19 Oct 2019, 13:51

You have one of the best Antique Outboard events in the country in Constantine! Folks from all over the country attend that one.

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18hp Johnson 1963 white smoke and full choke

Post by Kismet » 19 Oct 2019, 17:10

Even after all these years, I am still struck by the generosity and good-will of the members (especially Pappy) to folks who find us and post their difficulties. In this case, the OP went to the trouble of documenting his labors, showing results, and maintained the communication to-and-fro which will allow others who come across the thread to learn and repair the old motors. Thank you, as well, sir.

My salute to goodness of spirit and excellence of advice of those in this thread, and in so many others. You folks make the world a better place.

=D> =D> =D> =D> =D> =D> =D>
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