Briggs & Stratton 270962 Electric Starters, SYSTEM 3, SYSTEM, Model Series 97700, 99700, 110000

ELECTRIC STARTERS

Before assuming an electric starter requires service, check the engine for freedom of rotation by removing the spark plug and turning the crankshaft over by hand. Any belt, clutch, or other parasitic load will affect the starter cranking performance, so ensure their effects are minimized.

The following list is given to aid in diagnosing problems for 12 Volt and 120 Volt starting systems.

1.Engine Cranks Slowly

•Parasitic load affecting performance

•Discharged, defective, or incorrect battery (also, see alternators)

•Faulty electrical connection (battery circuit)

•Dirty or worn starter motor commutator, bearing, weak magnets, etc.

•Wrong engine oil viscosity for ambient temperatures

•Defective starter clutch

•Band brake misadjusted

•Battery leads too long or wire diameter too small

•Extension cord longer than 25 feet (7.60 mm) (120 volt AC only)

2.Engine Will Not Crank

•Faulty safety interlocks

•Discharged or defective battery

•Faulty electrical connections

•Faulty starter motor switch (open circuit)

•Open circuit in starter motor

•Defective rectifier assembly (120 Volt AC only)

•Brushes sticking, etc.

•Faulty solenoid

•Blown fuse or tripped breaker at power source.

3.Starter Motor Spins But Does Not Crank Engine

•Sticking pinion gear

•Damaged pinion or ring gear

•Starter motor clutch slipping

•Incorrect rotation due to reversed motor polarity (all motors rotate counterclockwise, as viewed from pinion gear)

4.Starter Motor Blows Fuses - (120 Volt Starter Motor Only)

•Parasitic load

•Shorted rectifier assembly

•Shorted 120 volt extension cord to starter motor

•Armature shorted

•Overloaded circuit

5.Starter Motor Spins But Will Not Stop

•Defective starter switch

•Defective solenoid

SYSTEM 3®, SYSTEM 4®

Model Series 97700, 99700, 110000, 120000

Both of these systems consist of a starter motor (A, Figure 33), starter switch, interlock switch (B), and solenoid (optional). When the starter switch or solenoid is actuated, the battery supplies power to the starter motor, cranking the engine. When the engine is running, the alternator (C) recharges the battery.

Figure 33

Check Starter Motor Drive and Clutch When starter switch is activated, pinion gear (A, Figure 34) should rise, engage flywheel ring gear, and crank engine. The pinion gear must rotate counterclockwise, as viewed from gear. If starter motor drive does not react properly, check helix (B) and pinion gear for free operation.

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