2004-2009 Honda TRX450R/TRX450ER Service Manual, Page 485Get this manual
ELECTRIC STARTER (TRX450ER) 7Starter Relay Switch Inspection Check the function of the starter relay switch (page 23-13)Does the starter relay switch function properly? NO YESFaulty starter relay switch- Loose or poor contact of the starter relay switch connector terminal
Starter Motor Turns Slowly Low battery voltage Poorly connected battery cable Poorly connected starter motor cable Faulty starter motor Poorly connected ground cable terminal Starter Motor Turns, but Engine Does Not Start Faulty starter clutch or starter gear train (page 14-15) Faulty ignition system (page 22-6) Starter Relay Switch Clicks, but Engine Does Not Turn Over Crankshaft does not turn due to engine problems