Kill Cord on an old Johnson

Sandro

Sandro

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Hi there,

My Drascombe Dabber Giulia is driven by a 2 stroke Johnson 4hp of 1984 that does not feature a kill cord switch.
As I often sail/motor single handed, would it happen to me an unintentional fall over the side, it would not be a pleasant one the sight from astern of her chugging merrily away leaving her master bobbing in the wake.
I considered a few options, none of which looks practically viable:
1) Leading out of the flywheel plate two wires paralleled to the points and using a modern kill switch and cord by the trade.
2) A loaded spring, triggered by the kill cord, pushing the throttle control all the way down.
3) A rubber flap shutting the air intake.
Is there anybody that has confronted the problem and can suggest a solution?
Of course I wear a harness when single handed but neither being towed in the water is a pleasant experience, let alone the propellor danger.
I am posting this question both on the Practical Boat Owner and on the iboat/Johnson & Evinrude Outboard forums. I expect that multiple posting is not against forum etiquette. It’s just to widen the search.

Sandro
 
change the stop button for one of the kill cord variety, depending on your current arrangement you will either need one that breaks connection to the points or one that shots the points to ground so to speak.

The majority of those that use the cords are conections made with the cord in.

I have added these before for people, look at some of the outboard spares people online who hold cheap second hand parts.

steve
 
You do not give the full model details but I assume you do not have a separate stop button at present and that the engine is stopped when the throttle control is shut right down. ??

If correct then yes a pair of wires from the points to a modern kill switch with safety lanyard is one way to go.

With an existing kill switch you would have two options. Replace with one with a safety lanyard or fit one in parallel to the existing one


For the iboats thread if anyone is interested see http://forums.iboats.com/showthread.php?t=370913
 
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Kill Cord

Steve, there is no stop button. As Vics correctly supposes, the standard way to stop this engine is by the throttle all the way down.
Yes, the electric solution is the cleanest.
I am afraid that I shall have to tackle the removal of the flywheel.
I shall post the results.
Thank all,

Sandro
 
Kill switch

For a completely different approach if you are using a harness with a tether perhaps another tether to either the o/b tiller or to the ships tiller a little shorter than the main tether and such that any load as in you falling overboard will pull the tiller hard over causing the boat to go around in tight circles.
Of course if it is a proper tether system it should be so short that you can not go overboard and that is a far better arrangement. If you go overboard under motor or sail and are on the end of a long tether it is unlikely that you could get aboard again. I have tried it the pull load is just too much even at 3 knots.
good luck olewill
 
I am afraid that I shall have to tackle the removal of the flywheel.
Click to expand...
Yo will need a "Harmonic balancer puller" that bolts onto the flywheel. You should see 3 threaded holes there for it. Use high tensile, grade 8 bolts.

I expect they will be an American thread UNF , or UNC, not metric The folks on iboats should be able to tell you the bolt size.
 
Kill cord

William, to upset the boat balance is the way I plan to use for sailing, I don't yet know how.
With just the main tether, may be braking from one side, the boat might round up and stop.
When motoring, I would not like the boat coming back to me in a circle because of the live propellor. Better cut off the engine.
Unfortunately the boat is so small that it is not possible to use a tether so short to keep me inside the gunnels. I should be bolted down to the floor boards.
About being towed, if I success in finding the way to stop the boat, the tow should finish very soon.
VicS, i don't know what a "Harmonic Balancer Puller" is. The puller I have is made by a cross bar through which is threaded the push down screw and by two adjustable pull up legs. When I get the correct three screws (for sure not metric) I shall make a thick plate with three holes and a central larger one for the puller screw. I plan not to use the puller legs but to pass the cross bar under the plate instead - the three screws must be long enough.
Then all the tricks used in this cases will be put to work.
Thanks again,

Sandro
 
Kill cord

William, to upset the boat balance is the way I plan to use for sailing, I don't yet know how.
With just the main tether, may be braking from one side, the boat might round up and stop.
When motoring, I would not like the boat coming back to me in a circle because of the live propellor. Better cut off the engine.
Unfortunately the boat is so small that it is not possible to use a tether so short to keep me inside the gunnels. I should be bolted down to the floor boards.
About being towed, if I success in finding the way to stop the boat, the tow should finish very soon.
VicS, i don't know what a "Harmonic Balancer Puller" is. The puller I have is made by a cross bar through which is threaded the push down screw and by two adjustable pull up legs. When I get the correct three screws (for sure not metric) I shall make a thick plate with three holes and a central larger one for the puller screw. I plan not to use the puller legs but to pass the cross bar under the plate instead - the three screws must be long enough.
Then all the tricks used in this cases will be put to work.
Thanks again,

Sandro
 
William_H said:
For a completely different approach if you are using a harness with a tether perhaps another tether to either the o/b tiller or to the ships tiller a little shorter than the main tether and such that any load as in you falling overboard will pull the tiller hard over causing the boat to go around in tight circles.
Click to expand...

Not so nice when you're in gthe middle of that tight circle!
 
VicS, i don't know what a "Harmonic Balancer Puller" is
Click to expand...

See HERE to see what a "harmonic balancer puller" is. It is called that because it is used to pull harmonic balancers ... ( but I haven't the faintest idea what they are :D )

You now know that the holes are 1/4" UNC if you are up to date with your post on iBoats ..... I dont know why I did not go and look at my 6hp sooner ... bound to be the same.

Ask on iboats what the correct torque is for the flywheel nut and also confirm that the key fits with its straight side parallel with the axis of the shaft , not parallel with the taper.

Inspect /clean /reset your points while you have the flywheel off.
 
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For simplicity, why not put a tether round the HT lead to the spark plug that will stop the engine dead if pulled off.
 
For simplicity, why not put a tether round the HT lead to the spark plug that will stop the engine dead if pulled off.
Click to expand...
It's a twin for starters and the plugs are pretty well hidden under the cowling. Also not screwed in straight, far from it, you would have to be sure you fell over the starboard side to get the pull in the right direction.
 
Steve28: yes; just two cylinders, two plugs, two ht wires.
Doghousekeeper: right.
VicS: I saw that a "Harmonic balancer puller" is just a puller. Mine will do the same job.
Thank you for the advises. The key position was new to me.
FullCircle: too violent - and see VicS's post of 19:32
Shall look for the screws.

Sandro
 
been thinking about this, i now think the way to go is via the choke knob, retro fit a press stud to the face of the control, the type you get for covers on awnings. then make up a kill cord with the opposite of the stud on one end.

what will happen is if you go over it should pull the choke out and stop the engine.

you may need to slacken the spring that presses down on the knob inside if it has one.


regards

stephen
 
kill cord

I had considered the choke option but it is not sure wether the motor would stop dead or limp away. I made some test in a water tank: result not clear.
Anyway the press stud is a good Idea.
Thanks
 
I once had an old Evinrude 4hp twin and considered using the choke as a kill switch. Once fully warmed up it would always stall if the choke was pulled out.
 
i now think the way to go is via the choke knob
Click to expand...

Unless there is very good reason not to, the way to do is with a purpose designed kill switch and safety lanyard.

Leave all these other lash-ups to William Heath Robinson
 
Kill cord for an old Johnson 4hp

Hi everybody,

glad to post that I have happily accomplished the job of the safety kill cord.

I found the american thread screws, I removed the flywheel rather easy, I connected and led out of the magneto two temperature resistant wires, I made a dry test touching toghether the two wires while the engine was running in a water bin: it stopped. I bought an emergency switch from a chandler, found for it a place clear of the flywheel, fitted and connected it. Reassembled everything.
A test on the water will take place as soon as the season will allow.
I sent the description of this modification, along with some more I did on the same motor, to
PBO Practical Projects. If it will be published you will see more details and some photos.

Thank again to all.

Sandro
 
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