Ignition Shorting?

[93Johnson]

I had a stalling problem last Fall when I would go into a low idle with my 1993 15 HP Johnson outboard.

After paying a lot of money to have the carb adjusted with little improvement, the shop suggested they replace the head gasket. With what their shop rates were I decided to do it myself. (I have zero mechanical experience.) I was able to do that with no problems (thanks YouTube) and I also replaced the fuel pump. I took it out to test it and had the same problem with an additional one - the ignition is constantly trying to start on its own. I took the cable off the negative terminal and if I even touch it to the post it tries to start. I took photos as I was taking the motor apart to get to the head and I am pretty sure that I have reassembled correctly. The red wire from the battery and the red wire from the ignition and one other small red wire all go on the same post? I cant see what I have done wrong. Any ideas?

 

[Crosbyman]

if you are saying the engine wants to crank on its own all the time....then the starter is being fed +12v constantly on its big red fat 12v post. follow the wire to the selenoid

that juice is from the selenoid relay which is either got its internal contacts welded shut thereby sending permanent +12 to the starter.

OR... the selenoid itself is being activated by a source of +12 on its control post (small individual post with one wire coming from the switch.......


probably the switch is sending a permanent 12v to the selenoid (stuck on start, defective guts etc... (small possibility of a short to +12v source between the motor and key)


step one disconnect the control wire from the switch at the selenoid
if that stops the starter.. problem is from the switch sending a solid +12v to the selenoid on that very same wire..... that condition is normally a very momentary thing when you turn the key to start. whatever the condition clear the permanent +12 on that wire !! .

if you disconnect the control wire on the selenoid and the starter keeps going then the selenoid is the likely suspect... give it a "controlled wack" to see if it will release the internal contacts and stop the starter operation. If that happens you know the internal contacts are fried and will stick together on a whim.... at the worst occasion.

 

[93Johnson]

Thanks. I should have said - no key. a push button for the electric start. Now - to figure out what a solenoid is....

 

[93Johnson]

On the photo that i included, is the solenoid the round silver part. Maybe I should just find out where to buy one and replace it?

 

[Crosbyman]

don't guess and spend needless money ... that simple 2 wire push button may be faulty..

first thing to do is locate the selenoid and remove the single.. smaller wire.. see picture
bolted on the side somewhere. if starter stops spinning go back to that push button and disconnect the same wire at its extremity.

if starter stops ...the button is stuck ON inside and needs replacement with an identical one for looks or a common car starter button available everywhere


If the starter DOES NOT STOP....that wire is frayed and shorted to some +12somewhere between the button and the selenoid.... twist turn poke the wire harness back to the engine till the starter stops spinning ...fix the wire !

btw... The red wire from the battery and the red wire from the ignition and one other small red wire all go on the same post? No they don't ! one is the control wire from the switch and needs to be alone on the single control post

 

[Vic.S]

On the photo that i included, is the solenoid the round silver part. Maybe I should just find out where to buy one and replace it?

With 3 yellow wires and a red wire ? ....... No that's the rectifier.
The solenoid looks like the picture attached.

Note it has two large screw terminals, which are the connections to the contacts and two smaller terminals, which are the connections to the energising coil..

Follow the heavy red wire from the starter motor and you will find it.
It will also have the main +ve feed from the battery connected to one of the large terminals

The two most likely reasons for your trouble are:

Either the solenoid is faulty ( contacts stuck ON )
or
The starter button is faulty ( stuck on)

Check both and replace which ever is faulty.

 

[Crosbyman]

just follow the fat red wire on the starter.... back to the selenoid OUTPUT POST ... the other fat post (INPUT) has a fat 12v from the batt. and smaller 12 v wires from the rectifier (the one with 2 yellows)

and the other smaller bolted wire is the CONTROL wire from the start button

just disconnect it and post results here for further help.

 

[racerone]

Wiring and 12 volts is confusing.

 

[Crosbyman]

Wiring and 12 volts confusing...

Not really... learning is a slow process which grandma explained very well when I was a kid.

the human brain is like bottleneck. If you try to fill the bottle to fast you spill most of the liquid . Yet as time goes by the underlying objective is reached.

93johnson will see is problem fixed with encouragement and expert coaching from S.M.E's and crow eaters like me.

 

[93Johnson]

Guys. Thanks so much. I still can’t find the solenoid but I found the problem. I undid the gear shift (f-n-r) and popped the starter button off. The button shaft inside the starter mechanism was stuck. I pulled it out with some needle nose pliers and put it back together. That problem is now solved.

Thanks again. Now I just need to figure out how to tune this carb. The motor starts with the choke pulled out but when I push it in it only runs for 10 - 15 seconds. I can get it to run longer by playing with the choke so I am assuming it’s just some adjustments. All suggestions welcome.

 

[Crosbyman]

I still can’t find the solenoid... flow the fat red wire on the starter !! there is only 1
(just follow the red brick road)

Glad you found the stick buton !

you are on your way to become a carb expert

if you are overly concerned you can try a half bottle of engine clear in a fresh load of fuel while choking it to have it suck in the magic mix

maybe...you will be lucky if not..... well you have to unbolt the animal flush and blow all passages .. reinstall (visit utubes... they are good ones)

NO CARB cleaner on the float if it is cork !!

 

[oldboat1]

You need a factory manual for your motor! That should be the starting point for trouble shooting and repairs.

 

[93Johnson]

I took the boat out on the water today. It fired right up and I let it idle for a good 5 minutes. (no more run and gun and using premium gas). The motor performed ok but I can feel a serious loss of speed over the years. When I would reduce the throttle to low idle it would cut out like it always did. This time however I brought my screw driver and was able to adjust the ‘screw’ and prevent it from stalling. So, that’s good.
As things often go with old motors and after turning off the it off to enjoy the quiet, I found that when I went to restart there was nothing. Bilge pump, electric motor and fish finder all continued to work. I checked the terminals on the battery posts and everything was fine. My guess is the electronic ignition button. Any other guesses Or advice? Thanks.