Merc 25 HP 2 Stroke Stator Question (1991 model)

[dthx]

This engine only fires on one cylinder until the RPM gets up and then the other cylinder kicks in.
Assuming plug gap, coils, switch box, carb, etc, and everything else is OK....
What relationship Is there between the trigger output at some higher RPM and the Stator output?
I'm thinking that both cylinders should fire...... even at low RPM.

 

[flyingscott]

Look at the switch box 9 times out of 10 that is failing. Those motors have very good stators have never seen one fail.

 

[Chinewalker]

Could also be a coil going out, or even just a bad ground. Remove and clean the ground straps on the coils. Run the motor. If no difference, do a cylinder drop test to determine which is failing. Swap the green wires from the coils, then swap the top and bottom plug leads so the coils are swapped around top and bottom. Now note if the issue follows the coil. If it follows the coil, then there's your issue. If no change (for instance, top cylinder not firing in both cases) then it is likely the pack.

Only one trigger, so if it was going out, both cylinders would be affected.