# 18hp Johnson 1963 white smoke and full choke



## cosborn (Oct 7, 2019)

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!


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## Pappy (Oct 7, 2019)

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.


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## CedarRiverScooter (Oct 7, 2019)

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 (Oct 7, 2019)

Pappy said:


> 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.
> ...



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!


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## nccatfisher (Oct 7, 2019)

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


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## Pappy (Oct 8, 2019)

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 (Oct 9, 2019)

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 (Oct 10, 2019)

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 (Oct 13, 2019)

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 (Oct 13, 2019)

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 (Oct 13, 2019)

Pappy said:


> 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.
> ...



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.


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## CedarRiverScooter (Oct 14, 2019)

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 (Oct 14, 2019)

CedarRiverScooter said:


> 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? https://www.amazon.com/Etekcity-Multimeter-MSR-R500-Electronic-Multimeters/dp/B01N9QW620/ref=sr_1_5?keywords=ohm+meter+tester&qid=1571060588&sr=8-5

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


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## CedarRiverScooter (Oct 14, 2019)

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 (Oct 14, 2019)

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):





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.




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:


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## cosborn (Oct 14, 2019)

cosborn said:


> 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?).


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## cosborn (Oct 14, 2019)

Video of it running:

https://www.dropbox.com/s/csgm3rldrzxssni/Video%20Oct%2014%2C%207%2046%2021%20PM.mov?dl=0


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## CedarRiverScooter (Oct 15, 2019)

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 (Oct 15, 2019)

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 (Oct 15, 2019)

Pappy said:


> 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.


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## cosborn (Oct 15, 2019)

Pappy said:


> 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 (Oct 15, 2019)

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 (Oct 15, 2019)

CedarRiverScooter said:


> Congrats on getting it started again.



Thank you!



CedarRiverScooter said:


> 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.
> 
> ...



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 (Oct 15, 2019)

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 (Oct 17, 2019)

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/qdpdjndy8hdsro4/Video%20Oct%2017%2C%207%2017%2057%20PM.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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## nccatfisher (Oct 17, 2019)

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 (Oct 18, 2019)

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 (Oct 19, 2019)

Pappy said:


> 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!
> 
> ...



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 (Oct 19, 2019)

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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## Kismet (Oct 19, 2019)

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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