Need help please...

[Doinit]

Hi guys, I have a question about my key switch on a 100 hp 1968 evinrude motor. I have power at the switch and power at the selenoid but when I go to turn it over the starter won?t activate. All fuses are good and I had the selenoid tested and it checked out ok. It was working but not now,I am stumped. I also have power at my forward and reverse switich. When I tested the switch I got a light at the selenoid when a turned the key as if to start the motor on the small post at the selenoid. The starter won? t activate at the switch with just touching the wires to kick the starter over either.

 

[boobie]

Will your battery pass a load test ??

 

[F_R]

No Title

I'm having a bit of trouble following what you are saying. But I'm suspecting a bad safety switch. Or out of adjustment one. OR perhaps it is just doing its job, which is to prevent starting at high throttle settings. Try backing off on the throttle.

OK, having said all that, the FIRST thing you should do is make sure the battery is good. The second thing you should do is make sure the battery cable connections are clean and tight. Don't just look at them, remove and clean them shiny bright and reassemble tightly. This is just good practice.

If you still have trouble, use a meter to check the circuit, using the wiring diagram. Here ya go----

 

[oldboat1]

+1 ^^ (also suggestion to load test battery). In addition, think I would briefly jump directly to the starter just to be sure the starter isn't the issue (jump it from your vehicle to take everything but the starter out of the equation). Starter gear should snap up into the flywheel and crank the engine with no hesitation.

Rock the throttle handle back and forth a little in the neutral detent while turning the keyswitch. If the starter kicks in, pretty good bet it's a problem with the safety switch as suggested.

 

[Doinit]

The battery is fully charged and the starter turns over the motor by jumping the two big wires on the selenoid.i also did move the throttle back and forth but still nothing. I also cannot jump it over by bypassing the switch at the switch.

 

[Crosbyman]

SO the starter seems ok when you jump across the selenoid post
Causes......hum...

​1- Open winding inside the selenoid ( test with a ohmeter to see if you have continuity from control post to ground via the safety switch )

​ 2- You get a light at the selenoid control post (from the start key) which means the selenoid should kick in but doesn't... Touch that post with a solid wire from the BAT+12 post to see if it engages the selenoid . If it doesn't the selenoid is likely bad or stuck internally

If it does from the battery post .... then that 12 volts from the switch wire is good enough for a bulb but to weak to pull up the selenoid.

The cause is likely a resistive contact in the start contact inside your key switch or the source of that12v is resistive (recheck all +12 v wire routes and contact points for corrosion... clean and retighten all junctions)

​testing for voltages is fine but thoses wires must be able to carry enough amperage to get stuff to work so look for resistive points (oxydation-corrosion)


​ make certain the selenoid ground source from the safety swith is OK !! it may also be to resistive to allow a strong current flow to ground when to turn the key to start

 

[F_R]

The battery is fully charged and the starter turns over the motor by jumping the two big wires on the selenoid.i also did move the throttle back and forth but still nothing. I also cannot jump it over by bypassing the switch at the switch.

Your story almost screams out Safety Switch! Do you have a multimeter (voltmeter)? If you don't, do yourself a favor and get one. They are only around $10 at wal mart, home depot, etc.

Now that you have the proper tools, check the voltages at the two small posts on the solenoid while somebody turns the key to start position.

Battery voltage at both small terminals means the safety switch is bad, or is improperly adjusted, or throttle is set too high.

Battery voltage at only one small terminal is normal and the starter should run. BUT, if you have voltage at only one small terminal and starter does not run, then either the solenoid or starter is bad.

No voltage at either small terminal means the juice isn't getting that far. Check fuse, key switch, wires, etc

All this assumes you did the right thing and know for a fact that the battery and cables/connections are OK.

 

[Crosbyman]

Doinit said....." I also cannot jump it over by bypassing the switch at the switch."

​ this is confusing which switch is this??....... the START switch contacts or the safety switch


if the starter turns over by JUMPING terminals at the start switch then the start switch is bad (doesn't close it's internal contact to feed 12v+ to the selenoid )

If you mean...the safety switch ....that will provide a solid ground back to the selenoid and if a good +12 reaches the selenoid's other post ...from the START key it should pull and get the starter to turn over

Doinit ... as you said... the starter works fine when you jump across the 2 fat posts on the selenoid we must assume the battery is fine and the starter

bottom line....

follow the +12 juice

Bat +12v to start key

​ +12V at the Start key output contact.... to selenoid when you turn that key to start


​did you or not try to connect a good +12 to the CONTROL post on the selenoid ( THE CONTROL POST NOT THEOTHER ONE GOING TO GROUND VIA THE SAFETY SWITH !!!)

what was the result ???

 

[Doinit]

I will let you know what I find out, thanks

 

[oldboat1]

Try grounding the small solenoid terminal connected to the safety switch (jumper to battery neg. terminal), then try starting. If the starter fires, replace or adjust the safety switch.

 

[Doinit]

Well I found out that it was the selenoid, so now it turns over but still won?t run. I am getting gas and it fires but won't keep running,not sure why maybe I am flooding it? Does the safety switch have to be connected to the selenoid? Cause I just grounded that wire and hooked up the hot to the single post selenoid that a friend gave me. I was really just testing it but if it will run like that I can change it out later.

 

[F_R]

The safety switch prevents starting the motor at high throttle settings. That is its sole purpose. The way you have it now can be dangerous---like if you start it and run over something or somebody.

 

[Crosbyman]

are you saying both the original selenoid was bad (not operating( ??) and the safety switch open ???? you seem to have 2 events here and assuming a bad safety switch..... that should not have affected the selenoid itself (mecanically anyway)

why would you ground the safety switch wire (selenoid side )

​have you done any ohm readings on the selenoid inner winding (measuring across the two small posts) and a continuity test on the safety switch ??

 

[oldboat1]

The solenoid switch has to be grounded to work (i.e., to pass current to the starter). On your motor, the solenoid ground runs through the safety switch, which grounds the solenoid when everything is working properly. If the starter doesn't fire unless you ground the small terminal with a jumper, the safety switch is the likely problem.

I agree the problem is probably not the solenoid, and that you should do a simple continuity test on the safety switch.

 

[Doinit]

Need help please

Hi guys, I am still having trouble with this 1968 100 hp evinrude motor. The only way it stays running is if I hold the key in the on position with the starter still engaged. I have put a new solenoid on it but it did not fix the problem. I don't know where else to look other than the starter, could it be the starter?

 

[alldodge]

Might need another key switch. Check the connection between the magneto and ground. If the key when released to RUN the magneto goes to ground, this is what is killing the motor

 

[roffey]

Here's me thinking on paper, It cant be the starter or solenoid as it kicks out the bendix to start the motor. Could it be a fuel pump that maybe only works when turned to start but not run. I'm thinking a power issue, wiring?

 

[Ned L]

Might need another key switch. Check the connection between the magneto and ground. If the key when released to RUN the magneto goes to ground, this is what is killing the motor

This is where I would look

 

[Doinit]

Or maybe a ground? Is the magneto in the key switch? I did replace the key switch but it is still not working

 

[racerone]

There is no magneto on a 1968 model 100 hp.----What switch did you install and what wiring diagram did you use.