Coil Cap Ignition Technology

Lift the hood and take a look at the cylinder head and spark plugs on a Yamaha 4-stroke and you will not find your familiar plug caps and high-voltage leads from the coils. Rather, you find what is called “coil caps” on top of the spark plugs, integrated units that combine the coils right into the spark plug caps themselves.

This arrangement has many obvious benefits when it comes to consistent firing of the ignition system and spark plugs. There are no plug wires to deteriorate or arc, so the voltage from the coil is going to be delivered properly to the plug terminal far more consistently.

However, owners of 2003 model year RX-1s will want to pay attention to the possibility of misfiring due to a loose spring clip inside the coil cap, as the spring clips were changed starting with the 2004 model year. If you notice notches or physical wear on the plug terminals, replace the old-style coil caps with the newer version; p/n: 8FA-82310-01-00.