| Page 9 - Index - Page 11 |
Force with Mercury Designed Ignitions
(1992-1999)
|
| Two Cylinder Engines Using a Separate Switch Box and Ignition Coils
|
No Fire At All:
- Disconnect the black/yellow kill wire AT THE PACK and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or shift switch.
- Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier.
- Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly.
- Check the stator resistance and DVA output as given below:
|
| Motors with Black Stator
|
| |
Wire |
Read To |
Resistance |
DVA |
|
| |
Blue
Red |
Blue/White
Red/White |
3250-3650
75-90 |
180V or more
25V or more |
|
|
| Motors with Red Stator
|
| |
Wire |
Read To |
Resistance |
DVA |
|
| |
White/Green |
Green/White |
500-700 |
180V or more |
|
| Red Stator Adapter
|
| |
Wire |
Read To |
Resistance |
DVA |
|
| |
Blue |
Engine Ground |
Open |
180V or more |
|
|
No fire or Intermittent on One Cylinder:
- If the cylinders are only acting up above an idle, connect a inductive Tachometer to each cylinder in turn and try to isolate the problem cylinder.
- Check the trigger resistance and DVA output as given below:
|
| |
Wire |
Read To |
Resistance |
DVA |
|
| |
Brown wire (#1)
Brown wire (#1)
White wire (#2) |
White wire (#2)
Engine GND
Engine GND |
800-1400
Open
Open |
4V or more
1V or more (a)
1V or more (a) |
|
- This reading can be used to determine if a pack has a problem in the triggering circuit. For instance, if you have no fire on one cylinder and the DVA trigger reading for that cyli?lder is low — disconnect the trigger wire and recheck the DVA output to ground from the trigger wire. If the reading stays low — the trigger is bad.
- Check the DVA output on the green wires from the switch box while connected to the ignition coils. Check the reading on the switch box terminal AND on the ignition coil terminal. You should have a reading of at least 150V or more at both places. If the reading is low on one cylinder, disconnect the green wire from the ignition coil for that cylinder and reconnect it to a load resistor. Retest. If the reading is now good, the ignition coil is likely bad. A continued low reading indicates a bad power pack.
|
Engine will not rev beyond 3000-4000 RPM:
- Connect an inductive Tachometer to each cylinder in turn and try to isolate the problem. A single cylinder dropping fire will likely be the switch box or ignition coil. All cylinders acting up usually indicate a bad stator.
- Connect a DVA meter between the stator’s Blue wire and Blue/White wires. Perform a running test. The DVA voltage should jump up to well over 200V and stabilize. A drop in voltage right before the problem occurs indicates a bad stator. (Blue to Engine GND if the engine has a Red stator kit installed).
- Connect a DVA meter between the stator’s Red wire and Red/White wires. The DVA voltage should show a smooth climb in voltage and remain high through the RPM range. A reading lower than what is on the Blue wire indicates a bad stator.
|
High Speed Miss:
- Connect an inductive Tachometer each cylinder in turn and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the switch box or ignition coil. Occasionally a trigger will cause this same problem. Check the trigger as described above under “No fire or Intermittent on One Cylinder”.
- Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
- Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.
|
| Page 9 - Index - Page 11 |
