Capacitor for YAMAHA YZF and WRF 450 four-strokes. On these fuel-injected bikes, most of them kick-started and without a battery, the capacitor stores the energy produced by the alternator and stabilises the circuit voltage: it allows the fuel pump, injector and ECU to work from the very first kicks.
A worn capacitor shows up as hard starting, misfiring or an engine that stalls at idle, even though the plug and injection are fine. Replacing it is a simple, inexpensive repair worth trying before looking for a bigger fault. The BIHR unit offered here fits in place of the original part; check your bike's year in the product title.
Use the vehicle selector at the top of the page to display only the parts that fit your bike.
