I think it's the Key/Ignition - what do you think

[Keepseln]

Ok guys,

Let me start with, this site rocks and I consider it to be an invaluable tool for boating. Now here is the story, I have a 1989 suntracker party barge with a 90hp 2 stroke Mariner engine (serial #b175157). I keep the boat in a slip on the lake and it?s been a blast all year long.

Usually when we go out on the boat the initial start up is a pain, and it?s taking many trips to identify what?s actually happening.

Turn on the main power/battery switch
Pump the fuel bulb until hard
Crank the engine

Now if it doesn?t immediately start up, I know it doesn?t have spark. Remember this has been all summer, and every time I jump back and check for spark first. The fix it seems has been to turn the main battery switch to off let it sit a few minutes and start over. After 3 or 4 tries the engine fires right up and no more problems for the rest of the day. I think the problem is with the ignition switch itself, I?m hoping someone here might have some insight.

Thanks in advance for the help

 

[CharlieB]

Re: I think it's the Key/Ignition - what do you think

Easy enough to check with an ohm meter.

The ignition switch is a ground to kill, in the OFF position it connects the black w/yellow trace to the Black ground wire.

Next time it won't start, leave the switch in the ON position and test the black w/Yellow trace wire on the back of the switch, ohms to the Black ground wire.

If ANY continuity, unplug the black w/yellow wire from the ignition switch and re-test BOTH sides.

If the ignition switch side still has continuity then the switch is bad.

If the engine side has continuity then you have a problem farther back in the harness or at the engine.

While disconnected from the ignition switch you should have spark, however you will no longer have a kill switch unless the lanyard still works.

 

[Keepseln]

Re: I think it's the Key/Ignition - what do you think

Thanks for the info

My particular switch has epoxy. I don?t see a way to disconnect anything. It?s been my intention to put in a new ignition switch this winter, any thoughts on where to get one for this motor?

-JB

 

[hkeiner]

Re: I think it's the Key/Ignition - what do you think

My particular switch has epoxy. I don?t see a way to disconnect anything.

You do not have to take the ohm/voltage/ground readings at the switch itself. All the wires from the switch go somewhere else, where you can do the testing. As previously suggested, using an ohmmeter/voltmeter is the best way to systematically troubleshoot the problem. Replacing the switch without first confirming that it is the culprit may cause some frustration...

 

[sschefer]

Re: I think it's the Key/Ignition - what do you think

WIthout knowing the boat or it's wiring, I might be inclinded to look for a ignition relay as being the culprit. It will usually be a small silver metal or black plastic box shaped electrical component that's in line with the ignition at some point. Sometimes they click when you turn the key to the on position. There purpose is to absorb the load if you have all of your lights, etc, on when you flip the power switch on.

If it is hanging, it may take a couple of flips of the main power switch to knock it back into action (so to speak). If you happen to find a relay, try tapping it a couple of times with the handle of screw driver. It might just be the culprit.

 

[hamit59]

Re: I think it's the Key/Ignition - what do you think

I would check the Mercury safety switch and the lanyard switches also can cause you to not get spark You need to trace out the black and yellow wire to make sure your not grounding.

 

[sschefer]

Re: I think it's the Key/Ignition - what do you think

Don't know if you've fixed this problem or not but the relay that I mentioned is a possibilty. I just tore out the wiring on my Starcraft and found one layed up under the dash. I havent had time to trace it all the way back yet but it is definitly on the ignition switch. I'm pretty sure it's not the turn signal flashers.

 

[Mac uk]

Re: I think it's the Key/Ignition - what do you think

Dont know the controls on your boat but mine has a nuetral dead switch in it. If its not in nuetral iy wont start. Its a roller switch in the control unit.

Just a thought

 

[Baja16SS]

Re: I think it's the Key/Ignition - what do you think

Have you been able to verify that there is no spark?

I am a service tech at a Tracker dealership and many of our customers have a hard time starting the 2-stroke motors.

My starting procedure for all the 2-strokes is:

-verify safety lanyard
- squeeze primer bulb till firm
- advance throttle in "Throttle only" position about 1/4 of the way. You'll feel resistance once it passes the shift section and starts to move the throttle cable
- push in and hold key to engage choke while cranking motor
- control rpms with throttle lever and tap key to engage choke if it starts to die

-The neutral safety switch mentioned above only disables the starter while in gear. It does not affect spark.

There is a black wire with a yellow trace (yellow line) on the motor and in the harness. This is the "kill" wire. When it is grounded through the ignition switch, it stops the spark and shuts off the motor.
Depending on the motor, there may also be a rev limiter ( thin black box 4"square or so) that can cause a no spark situation. The black/yellow wire goes through it as well.

I don't remember a "main power relay" involved in the ignition circuit on carburated motors. They usually power up the Engine Control Module on EFI motors.

I'd try my starting procedure before replacing the key switch.

 

[sschefer]

Re: I think it's the Key/Ignition - what do you think

This post was started last month but just in case you haven't found the cure yet, let me ask this..

When you put the boat in the slip and leave it, is the motor at full up tilt? If so, there's a mercury switch that cuts off spark so that the engine can be tilted up and turned over but no spark will occur and it can't be started. I could see where after tilting it up and down a couple of times checking for spark etc., might just cause it to start working again.