holds starter for 0.5 seconds after release – don’t keep the button pressed. If you do, you may damage the starter clutch. The manual only hints at this.
The GR 150 features a Euro II compliant, 4-stroke, air-cooled OHC engine. It is designed for both efficiency and durability, making it a popular choice for urban commuting and touring. Suzuki Gr 150 Owners Manual