Mercruiser Thunderbolt Ignition Components
Here are a few simple tune-up tips.
1. Check for deposit build-up inside your distributor cap.
2. Always replace the sensor wheel along with the rotor.
3. Make a note of your firing order BEFORE the tune-up.
5. Make sure you have the correct engine specifications.
6. Use White Out to mark your harmonic damper timing line.
7. Use care installing a ThunderBolt Sensor wheel! Don't bend any tabs.
8. Never over-tighten the sensor unit mounting screws.
9. Make sure your distributor ground wire is properly fastened.
How do you know if you have a Thunderbolt Ignition System?
There are a few differnt ways to indentify which type of ignition system you have.
One of the simplest methods is to look inside cap.
If you remove the cap you can see the Thunderbolt IV or Thunderbolt V sensor unit.
The sensor is underneath the rotor and sensor wheel assembly.
V6 rotor/sensor wheel assemblies are NOT THE SAME as the V8 rotor sensor wheel assemblies.
Although they do look very similar
The Thunderbolt IV and Thunderbolt V systems have similiar Caps, rotors and sensors.
Earlier Thunderbolt IV sensors uses brass nuts for attaching the harness wires
Newer Thunderbolt IV and Thunderbolt V sensors used bullet connectors.