Newly acquired Johnson Jw-10 needs Carb Rebuild at least

[Michael Gehrling]

Good day,

Just acquired a Johnson JW-10 (Actual Model and Serial number JWW100 & 1202121) with a carburetor that leaks fuel. I am looking for links to repair manuals and videos on this carb rebuild.  Trying to collect all information I can before I take her apart. Suggestions for a new AOMC member is appreciated.

Mike

[aquasonic]

Mike, the OMC carburetor kit is P/N 439071. Ebay is a good source for one. Look for best price and free shipping. Avoid the Chinese aftermarket kits and stick with the OMC one. The aftermarket kits are less expensive, but I wouldn’t even want one for free. They have a multitude of issues.

The rebuild is relatively simple. There should be a how-to video on You Tube. Please use proper sized wrenches on the tiny bronze compression fittings on the fuel lines.

Once apart, soak all parts in your choice of carburetor cleaner overnight, then clean and rinse with fresh water, blow out all passageways with compressed air, and reassemble.

There is plenty of help here, so please ask.

 

Improvise-Adapt-Overcome

[outbdnut2]

Your JW-10 is a 1953. Good motor! and a smooth runner. If you get the OMC carb kit, it will have a new float in it. If not, you may have to dry out and reseal the old float if the protective coating is flaking off, which ethanol in gasoline attacks. I’ve resealed floats with hot fuel proof clear model airplane “Dope” that is getting hard to find. I’ve heard of people resealing them with superglue, but haven’t tried it. The lower unit gearcase takes marine gear oil – not grease, and you can use any marine gear oil except Type C, which is for electric shift motors.
The carb is an easy one to rebuild, just be sure you get the small, thick “donut” gasket on the part that hangs down to the bottom of the carb bowl, or it will flood when you speed it up. That is part #32 inthe view at the link below – it’s for 1957, but same as your 1953.
3 HP JW carb
Dave

[Michael Gehrling]

Dave,

Thank you.  I do love the simplicity of this engine.  Finding videos of JW-10s running after rebuilds, shows me just how smooth they can run.

I have rebuilt the carb twice with the original parts as I wait for the carb kit.  Removed most gunk. She is now running pretty good but, it could be better.  The tank was flush out many times and I still got old gas particles in the latest flush.  Soaking the tank with denatured alcohol now.

The original pull cord was frayed when I got it, of course it only got worse and I needed to replace it.  The rubber handle on the tiller is cracked in multiple spots.  I am guessing replacements for this is no longer available.  Any trick in regluing the cracked areas to save the rubber handle?

Best regards,

Mike

 

[seakaye12]

Michael you can get decent repro starter handles from places like North York Marine if you want to pay $50.00 plus shipping.

http://www.nymarine.ca/Estart.html

There are a lot of other choices if you don’t mind it not being quite so authentic in appearance.  Ben Breitner makes nice handles on a 3D printer and then of course there are the lawn-mower service parts which are always a fraction of anything with the word “boat” on it.

Pay close attention to the link-and-synch on your JW….and if you can set the points with one of the OMC timing tools that can also help get good idle quality.

Have you pulled the flywheel yet to have a look at the coils?  Hopefully they are genuine OMC coils in good condition.  The Chinese replacements IMHO do not spark as well at low RPM.

 

[seakaye12]

For Link and Synch of the Carburetor/Magneto Cam….refer to the two dots that Johnson has provided on the front cover.  See the Pic.  The other dot is under the throttle lever in the pic.  Place your throttle lever right in the middle between those two dots….and that is the point where the magneto cam should just begin to move the carburetor linkage.

 

[Michael Gehrling]

SeaKay12,

Thank you for the information.  I have not pulled the flywheel as of yet as the center nut is not cooperating.  From what I can see, it appears that the points and condensers are new, what brand I cannot tell.  I will try a bigger impact wrench on the center nut but just to be sure, to remove it is counterclockwise?

Thank you also for the picture of the two dots.  I checked and this is the point that the cam starts moving the carburetor linkage.  On the word “SLOW” I cannot get the throttle into the letter W as she will just get rough and stall.

Best regards,

Mike

[Michael Gehrling]

Good day Aquasonic,

Thank you for the information about OMC Carb Kit.  In looking at the parts of the kit it would seem that it may not be correct.  It appears that New Johnson Evinrude OEM Outboard Carb Kit with Float is numbered 439071 BRP/OMC Carburetor.  Could this be correct?

Thank you,

Mike

 

[seakaye12]

Michael Gehrling wrote:

SeaKay12,

Thank you for the information.  I have not pulled the flywheel as of yet as the center nut is not cooperating.  From what I can see, it appears that the points and condensers are new, what brand I cannot tell.  I will try a bigger impact wrench on the center nut but just to be sure, to remove it is counterclockwise?

Thank you also for the picture of the two dots.  I checked and this is the point that the cam starts moving the carburetor linkage.  On the word “SLOW” I cannot get the throttle into the letter W as she will just get rough and stall.

Best regards,

Mike

Yes Counterclockwise.  You really should use an appropriate puller.  If you need advise regarding that please ask.

[aquasonic]

Michael Gehrling wrote:

Good day Aquasonic,

Thank you for the information about OMC Carb Kit.  In looking at the parts of the kit it would seem that it may not be correct.  It appears that New Johnson Evinrude OEM Outboard Carb Kit with Float is numbered 439071 BRP/OMC Carburetor.  Could this be correct?

Thank you,

Mike

 

I sit corrected. Thanks for pointing that out. I corrected the original post to read “P/N 439071”.

Improvise-Adapt-Overcome

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