GS300 & SC300

Remove ignition coil. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article.
Using ohmmeter, check ignition coil primary resistance between positive (+) and negative (-) electrical terminals on ignition coil. See Fig 1. Replace ignition coil if ignition coil primary resistance is not within specification. See IGNITION COIL RESISTANCE table.

Using ohmmeter, check ignition coil secondary resistance between electrical terminal and spark plug terminal on ignition coil. See Fig 2. Replace ignition coil if ignition coil secondary resistance is not within specification. See IGNITION COIL RESISTANCE (OHMS) table. Reinstall ignition coil.

IGNITION COIL RESISTANCE (OHMS)

Application

Primary

Secondary

GS300 & SC300

Cold ⁽¹⁾

.33-.52

8500-14,700

Hot ⁽²⁾

.42-.61

10,800-17,200

⁽¹⁾	Cold is with temperature of 14-122°F (-10-50°C).

⁽²⁾	Hot is with temperature of 122-212°F (51-100°C).

Fig 1: Checking Ignition Coil Primary Resistance (GS300 & SC300)

Fig 2: Checking Ignition Coil Secondary Resistance (GS300 & SC300)