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Louie
Louie, Technician
Category: Motorcycle
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Experience:  25+ yrs. experience
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Why does a 1991 Yamaha warrior 350 have no spark? Have

Customer Question

Why does a 1991 Yamaha warrior 350 have no spark? Have replaced the following: Ignition coil, stator, pick up coil, CDI and spark plug.
Submitted: 2 months ago.
Category: Motorcycle
Expert:  Louie replied 2 months ago.

Hi Adam, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.

Initially and as it would appear to be an electrical/ignition issue, then proposed preliminary tries/checks (if have not been done) :

  • • check for IGN+12V on the red/black wire from the Engine Stop switch to the CDI unit;
  • • determine if there is pulsating voltage on the orange wire to the ignition coil from the CDI when attempting to start;
  • and verify presence of low pulsating voltage from the pick up coil to the ignition module;
  • • try with the clutch lefer pulled in;
  • • and check the drive select lever switch, neutral switch and the neutral relay including the internal diodes of this relay.
Customer: replied 2 months ago.
Thanks for the response and no worries on delay! In regards ***** ***** "checks" that you mentioned, could you explain on the following?"and verify presence of low pulsating voltage from the pick up coil to the ignition module"
-Do I need to pull the connector apart and how much voltage should there be?" and check the drive select lever switch, neutral switch and the neutral relay including the internal diodes of this relay"
-How do I check this? If these were bad, would the engine still crank?Thank you,
Adam
Expert:  Louie replied 2 months ago.

Hi again Adam,

On:

  • Do I need to pull the connector apart - preferably yes;
  • how much voltage should there be? - pickup coil produces low pulsating voltage ~500mV. It has to be posted that the prescribed test instrument for measuring output voltage of a pickup coil is peak voltage meter.
  • How do I check this? - continuity check with the multi-meter when ON and no reading when OFF;
  • If these were bad, would the engine still crank - yes and no. These are safety interlocks that requires combinations with the other switches. Something like, it will not crank if in gear but it will crank even if in gear but with clutch lever is pulled in.

Incidentally, I re-checked the wiring diagram and there is another coil co-located with the stator that produces high pulsating voltage to charge the cpacitor of the CDI.

Customer: replied 2 months ago.
Out of pure accident, when the kill switch is "off" and the quad is in neutral, it still wants to crank. With the switch in "run" position and quad in gear or neutral it still wants to crank. The clutch lever isn't pressed in....I tested continuity in the neutral safety switch and when I put the 2 leads on either side of the switch and depress the switch continuity is still there.
Expert:  Louie replied 2 months ago.

Almost always, a switch would have continuity between its 2 terminals if and only if in the ON position. Thus there should be no reading/continuity when in OFF.

Other than these switches, check also the neutral relay and its diodes.

Customer: replied 2 months ago.
The entire wire harness has been removed and the lines have been gone over. There are (3) relays not including the solenoid. Any ideas as to why there are (3) as it appears in a parts manual there are only (2)? I've tested these and one seems to be very weak (clicking) noise compared to the other two. This is blue in color and has (2) green, a brown and a black wire going to it.
Expert:  Louie replied 2 months ago.

Interesting.....even my copy of the wiring diagram shows only 2 + starter relay.

Post back with clear closeup picture(s) of the "...relay...blue in color and has (2) green, a brown and a black wire going to it...". Please click HERE.

Customer: replied 2 months ago.
Ok.
Expert:  Louie replied 2 months ago.

Thanks.

Bear with me, let me check all other versions / years and see if a wiring would match the 3-relay harness.

May not be that immediate as would be mobile later.

Customer: replied 2 months ago.
In addition, there is no "reverse" wire from the switch. I can't determine where it would connect to or what color wire it would be.
Expert:  Louie replied 2 months ago.

Based on the diagram, the reverse switch is to ground hence only 1 wire from the reverse switch; a green/light blue wire to the reverse indicator light.

Customer: replied 2 months ago.
basically I just need 1 wire from the switch straight to the reverse light up at the handle bars?
Expert:  Louie replied 2 months ago.

Yes; 1 wire from the switch to the reverse indicator light.

Customer: replied 2 months ago.
Morning Louie! I just wanted to circle back to see if you found anything that is referencing "3" relays?
Expert:  Louie replied 2 months ago.

Hi again Adam,

Unfortunately, no. None of the service manuals and wiring diagrams that I have uses a 3-relay system.

Still, based on the standard wiring of the YFM series:

  • black - ground;
  • brown - IGN+12V;
  • green - headlight.

Can you please trace/confirm to/from where the "...relay...blue in color and has (2) green...wire..."?

Customer: replied 2 months ago.
At this time, I don't feel like the harness is whole. I'm looking at a new harness as a solution. This extra relay has me concerned and since nothing can be solved, I'm at a loss.
Expert:  Louie replied 2 months ago.

Bear with me, let's re-start; let's review and re-check the basics:

  • do we have low pulsating voltage from the pickup coil when attempting to start;
  • do we have high pulsating voltage from the excite coil likewise when attempting to start;
  • is there consistent ignition on +12V on the red/black wire to the CDI.

Since the primary concern is "...no spark...", then consider just wiring/connecting the pickup, exciter coils to the CDI and the CDI to the ignition coil.