Trigger

[Schnidly]

Dear Forum, I may have to replace the trigger on my 1988 90hp 3cylinder Mercury outboard. Will it be required to re-time the engine if I replace it and install it in the same position as I took it off? I will mark the position I remove the old stator and position the new one the same way? I have never timed and outboard motor before and am a little leary of doing this. Please advise.

 

[CharlieB]

Re: Trigger

It is not that difficult and should be done when you change that trigger assy.

Remove all spark plugs and ground all spark plug wires. This will reduce the strain on both the battery and starter, and allow maximum cranking speed.

Rig a remote starter button to the starter solenoid. Shift into Forward gear, open the throttle to WOT, turn the ignition key On.

NOTE: BEWARE the prop will be turning, stand clear or remove the prop.

Rig your timing light on #1 spark plug wire, aim the light at the timing pointer, press the remote starter button and watch the timing marks, adjust max timing screw as required to bring WOT timing into spec.

Reinstall plugs, prop, etc.

Done.

 

[Schnidly]

Re: Trigger

Dear Forum, I know I said I am replacing the trigger, but let me ask you a question, if I am getting 4+ volts out of each of the trigger wires, brown, white and violet to the bias wire(black/white) wires connected on the switchbox would you say that my trigger is good? I am using a DVA adapter to check these voltages? My manual says 4+ volts and Im getting around 4-8 volts out of each wire.

 

[bilge rat jim]

Re: Trigger

You should also test resistance from each trigger coil, all should be 800-1400 ohms, or close. If the DVA reading is OK, but the resistance readings are out of spec, you may have a bad trigger. What are the symptoms that that led you to believe your trigger is faulty?
And, no, you do not have to re-time your outboard if you are replaceing the trigger.

 

[Schnidly]

Re: Trigger

Thanks Jim, I am getting intermittent spark, I will be cranking the motor and there is no spark on any of the plugs, using a spark tester. Then 10 minutes later I have all spark back. I have a new stator installed, and have voltage readings within specs going into the switchbox as read from a DVA meter, but no spark so I am leaning towards the switchbox being bad. After the engine starts, it seems to continuously start whenever I turn the key, but when it sits for a few days the same symptom occurs, it wont start, but then after awhile of trying to get her running she pops just like that. I am reading 1200 ohms on each of the trigger wires to the bias wire(white/black) on the switchbox, I do have all the wires disconnected from the trigger on the switchbox when I did this ohm test. I am also getting the open reading I should from each trigger wire to engine ground.

 

[bilge rat jim]

Re: Trigger

I think your trigger is ok, the switchbox is faulty. As a final test, disconnect the stop circuit (black/yellow) from the switchbox, to eliminate the possibility of gremlins in the stop circuit. If the symptoms stay the same, replace the switchbox. You may want to consider buying and aftermarket switchbox from CDI, should be part# 114-7778. In my opinion, CDI makes far superior ignition components than OEM from Merc, and at about 2/3 the price.

 

[CharlieB]

Re: Trigger

When it won't spark, immediately disconnect the Black wire with the thin yellow trace from the switchboxes to the wiring harness. This is the 'Ground-to-kill' wire. Now check for spark. If you now have spark your problem may be a faulty ignition switch, not dis-connecting the ground and it keeps killing spark.

 

[Schnidly]

Re: Trigger

Thanks Charlie, I did that and I still had nothing after disconnecting the kill wires off of the switchbox. Im still leaning towards the switchbox being an intermittent problem? Your continued input is much much appreciated. THANK YOU.

 

[Schnidly]

Re: Trigger

I replaced my old stator with a new CDI one, doing that because my old stator tested bad on the ohms test, the blue wire read 66,900 ohms to ground and the red wire was close to normal at 107 ohms.