From Sprinter - What are you getting? Starting System Symptoms: Weak battery symptoms: -- Slow cranking. -- Stops cranking suddenly on compression stroke with button pressed. -- Starts when starter button is released at end of cranking. Repair: -- Charge/Test/Replace battery. Failure Modes: -- Loss of capacity. Appears to charge, voltage good but no reserve for starting. -- Won't hold a charge. -- Low voltage/cell failure. Preventative Maintenance: -- Check fluid levels regularly -- Maintain full charge: Regular riding, trickle charger. Ignition Coil failure symptoms: -- Hard starting/misfiring during cranking. -- Rough idle that can't be tuned out with carb adjustments and carb cleaning. -- Idle misfire clears with new sparkplugs, returns in a few hundred miles Repair: -- Replace: Preferably with Nology for higher reliability than stock Gill coils. Failure Mode: -- Shorted turns in secondary resulting in weak spark. Preventative Maintenance: -- None Testing: Pickup Coil failure symptoms: -- No spark at all -- Spark quits with engine hot, returns when engine cool. -- Note: Pickup coil failure is total. There is no random misfire spark loss. Repair: -- Replace pickup coil Failure mode: -- Thermal intermittant with long (15-30 minute) period. Preventative Maintenance: -- None. Get a spare. Testing: -- Ohms checks hot and cold. Worn starter symptoms: -- Sometimes won't crank until the bike is rocked in gear. -- Excessively noisy cranking with a grinding sound. -- Click from under seat but no cranking. Failure Mode: -- Brush wear progressing to commutator damage. -- Bearing failure related to brush wear. Repair: -- Rebuild or replace. Preventative Maintenance: -- Maintain battery in peak condition. -- Follow proper starting procedures. Neutral, clutch in. -- Crank 5-10 seconds at a time max., switch off for twice as long before cranking again. Worn sprag clutch symptoms: -- Very loud rattling when cranking -- Starter spins but engine doesn't turn Falure Mode: -- Breakage Repair: -- Replace sprag clutch Preventative Maintenance: -- Maintain battery in peak condition. -- Follow proper starting procedures. Neutral, clutch in. Worn starter solenoid: -- Click from under seat but no cranking. -- Won't crank after rocking bike. -- Starter continues to run after bike starts and won't stop until the battery is disconnected. Failure mode: -- Internal contact damage resulting in non-conduction. -- Internal contact damage resulting in contacts welding shut. -- Internal damage/wear prevents solenoid core movement. Preventative Maintenance: -- None. Repair: -- Replace starter solenoid. Testing: -- For no cranking, short across solenoid high-power terminals. Normal operation denotes failed solenoid contacts. ------------------