# Johnson JW-10 - what can you tell me?



## pescadero (Mar 31, 2006)

My dad just gave me a non-running Johnson JW-10. He's had it for 10 years, but it just sat in the garage. Never ran for him. 

He tore the internals of the motor apart and everything looked good. Replaced the coils... then got lazy and never even tried to get it running. Now I have it... looking for any info on it I can get. 

I figure I'll check for spark, and if it has one throw some starting fluid at it to see if it will fire at all.

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lp


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## pescadero (Mar 31, 2006)

Motor: 1952-54 Johnson Seahorse (JW-10)

Pulled flywheel, adjusted timing/points, re-gapped plugs - now getting good spark

Motor fires up with some starting fluid, but won't run. Notice gas leaking out front of carb.

Tear apart carb, clean everything and re-assemble. Adjust float.

Same problem - Got motor to start and run for very short period, then it dies. Carb is leaking gas out the front- seems like it must be an overflowing float bowl, but float and needle valve looked good and functional. Once it dies it doesn't want to re-start, I'm guessing it is flooded.

Any ideas? Replace the needle valve and float? Re-adjust them again? Grit keeping the needle valve open? Some other issue with the carb I'm not thinking of?

Pic of carb in question:
http://www.outboard-boat-motor-repa...Outboard Boat Motor/images/3012 parts pg4.jpg

-- 
lp


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## GullLkRltr (Dec 13, 2005)

Any ideas? Replace the needle valve and float? Re-adjust them again? Grit keeping the needle valve open? Some other issue with the carb I'm not thinking of?

Without seeing it in person sounds like you're on the right track. I'd go with new float, needle and seat. Visual inspection doesn't always reveal the defect in needle and seat sealing capability.

Sounds like a neat old motor, have an old 10 horse Johnson myself over in the basement of my father's house. Don't know what year mine is but it's green, what color is your's- got a pic?


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## alex-v (Mar 24, 2005)

I had something years and years ago on an older motor. Same symptoms with the excess gas flowing from the front and the motor seemed to flood out and not start. In that case it was a worn seat. The needle showed a tiny bit of wear but not enough to cause a problem. But, it was very obvious where the wear was when the seat was pulled.


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## Take Five (May 10, 2003)

I have seen that type of float get gas logged and too heavy even though it looks like it is ok. I would replace the float also.

Wayne


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## pescadero (Mar 31, 2006)

GullLkRltr said:


> Any ideas? Replace the needle valve and float? Re-adjust them again? Grit keeping the needle valve open? Some other issue with the carb I'm not thinking of?
> 
> Without seeing it in person sounds like you're on the right track. I'd go with new float, needle and seat. Visual inspection doesn't always reveal the defect in needle and seat sealing capability.


Yeah... I'm going to pull it apart again and inspect things a bit better. Worse comes to worse I can always take it to work and throw it on the ultra precision measuring equipment :lol: 



GullLkRltr said:


> Sounds like a neat old motor, have an old 10 horse Johnson myself over in the basement of my father's house. Don't know what year mine is but it's green, what color is your's- got a pic?


This is what it originally looked like.

http://www.outboard-boat-motor-repa...d Boat Motor/images/Johnson_Seahorse-3-Ad.jpg

Mine is missing numerous bits and pieces, and what is there is not in so nice a cosmetic condition.

--
lp


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## pescadero (Mar 31, 2006)

Take Five said:


> I have seen that type of float get gas logged and too heavy even though it looks like it is ok. I would replace the float also.
> 
> Wayne


That is an easy one to test, so I'm going to test that and see what happens...

-- 
lp


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## Priority1 (Feb 5, 2006)

This has nothing to do with the carb problem, but you may want to replace the impeller if it's been idle for over 10 years. It could save your engine after going through all of this. By the way I luv those old Outboards.


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## Burksee (Jan 15, 2003)

...and stop using *starting fluid *to get it going! :yikes: Starting Fluid has no lubrication properties and will tear up a piston and cylinder wall of a 2-stroke motor faster than all get out!  

Get yourself a kit to rebuild the carb or take to someone that does it. Adjusting the gap on the points changes the dwell (timing) and you may have an issue there as well. You really need a dial indicator and a buzz box to set those up with properly.  

Also, as mentioned I'd put an impeller in it before it ever sees the water, cheapest insurance you can buy!


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## pescadero (Mar 31, 2006)

Burksee said:


> ...and stop using *starting fluid *to get it going! :yikes: Starting Fluid has no lubrication properties and will tear up a piston and cylinder wall of a 2-stroke motor faster than all get out!


Nah... the new starting fluid is lubricated, not straight ether like it used to be.



Burksee said:


> Get yourself a kit to rebuild the carb or take to someone that does it. Adjusting the gap on the points changes the dwell (timing) and you may have an issue there as well. You really need a dial indicator and a buzz box to set those up with properly.


Nah, timing is easy to set and I already adjusted it - you can do it statically with an ohmmeter and not even worry about measuring the point gap. No need for a dial indicator or buzz box. Just hook a lead to ground and a lead to condenser side of the coil, then rotate the flywheel and see where the points open. If they're opening too late, increase the gap. OPening too soon, decrease the gap.



Burksee said:


> Also, as mentioned I'd put an impeller in it before it ever sees the water, cheapest insurance you can buy!


I'll probably tank test it a bit before replacing the impeller, but I certainly won't take it out on any body of water without replacing it.

-- 
lp


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## greg123 (Oct 6, 2004)

Those old motors are pretty cool. Getting a 50+ year old motor running well is a neat thing to experience. The older marinas or dealers are good sources for parts. They may have the parts on a shelf somewhere or at least have the part numbers. I have an early 50's 5 hp merc that my dad bought new when he was a kid. With a couple new coils and carb rebuild it ran like a top. Haven't used it in a few years though. It sounds like a new needle and seat and possibly a float might be needed in your motor. Good luck parts hunting and remember to treat your parts guy well, a good one is worth taking care of. The good ones spend a lot of time looking for part numbers and maybe sell a 3.00 part. Treat him well. It will come back to you many times over.

Greg


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## pescadero (Mar 31, 2006)

A carb rebuild later (all new gaskets, new float, new float needle/seat)... 

...and it's still has gas leaking out front of carb. Not a lot of gas, but enough for a drip every couple seconds off the bottom of the float bowl. Got it to run for a while in the bucket last night, but - 

1) It seems to be running really rich from what I can tell.

2) It's still dripping gas.

3) It will only run at about 3/4 throttle (throttle position for starting) any more or less throttle and it just wants to die... and even when it is running at 3/4 throttle the RPMs seem WAY lower than they should - full throttle should be about 4000RPM on this motor.

4) Still doesn't want to start without a little starting fluid.

5) Seems to be running a little hot, so even though it is peeing water I'm not sure what state the powerhead water passages are in... So I guess I get to pull that apart next. How hot is acceptable at the cylinder head? It's certainly too hot to touch.


I'm at a loss on the carb/starting issues at this point - it really doesn't make ANY sense. This is probably the most simple carb I've ever seen (even more simple than the one on my old VW Microbus) and everything that should cause this problem (bad needle/seat/float/gasket) has been replaced. Everything looks good - the carb isn't full of varnish, all the passages are open, no cracks in the pot metal... The only possibilities I can think of are:

1) the missing air pre-silencer and its "low speed needle stop" - but even that doesn't make any sense because if the needle is screwed in too far it should be running too lean, and not too rich... 

2) Leaking air through the expansion plug (see part #48 in link below) - but again that should cause a lean condition, not a rich one...

http://www.outboard-boat-motor-repa...Outboard Boat Motor/images/3012 parts pg4.jpg

Any ideas/suggestions? 



I'd really just like to have a nice reliable motor for my little boat. 

My old motor (1.2HP Sears Gamefisher) is loud (aircooled) and underpowered - plus you can't get parts for it anywhere. 

This Johnson just won't behave, and I really don't want to dump the next month or a bunch of money into a motor I got free and not end up with something to show for it. 

I can't afford a good used motor, and I'd have to sell my children into white slavery to afford a new one. 

I think I'm cursed when it comes to outboards...

-- 
lp


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## pescadero (Mar 31, 2006)

I pulled it apart to check out the water passages - and that is the good news... everything was pristine, all the water passages were open and flow water easily. The heads on these things apparently tend to run a little hot, so it looks like no cooling issues.

The bad news... I pulled the carb completely apart again. Checked the float, needle/seat, etc. - everything looks perfect, and the float needle valve seals beautifully. No reason for it to be dribbling gas. I guess we'll see what happens when I get a chance to start it again...

-- 
lp


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## Westlakedrive (Feb 25, 2005)

I have a similar motor and similar issues. After carb rebuild leaking gas etc. I took some string and added it to the large idle screw to help seal up that valve helped some didnt totally solve the problem.


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## pescadero (Mar 31, 2006)

Westlakedrive said:


> I have a similar motor and similar issues. After carb rebuild leaking gas etc. I took some string and added it to the large idle screw to help seal up that valve helped some didnt totally solve the problem.


I might suspect the packing around the high/low speed needles, if that was where the gas was leaking from... sadly, it isn't - it is leaking right out the air intake. The needles aren't leaking at all.

-- 
lp


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