Upgrade the intake performance of your Yamaha mini motorcycle with Boyesen 674 dual-stage reed valve reeds. Designed to improve throttle response, airflow, and overall engine performance, these replacement reeds provide a practical performance enhancement for riders seeking stronger low-speed operation and improved engine efficiency. The dual-stage design allows the reeds to open and close more quickly, helping deliver better response across the engine’s operating range.
Boyesen 674 reeds are engineered to provide greater low-pressure, low-throttle response, increased velocity, and a larger effective flow area. This design can produce noticeable horsepower improvements with only a minor component change, while also supporting longer overall service life. The reed construction is designed so that an accidental break does not cause engine damage, adding durability and peace of mind during regular riding.
These Boyesen motorcycle reeds fit 1981–1988 Yamaha PW50 models and 1984–1985 Yamaha YT60 Zinger models. Verify the motorcycle model and year before installation to ensure proper application. Manufacturer part number 674 and vendor part number 674 identify this Boyesen replacement performance reed set.
Features:
- Dual-stage reed design for improved intake performance
- Minor component change can provide significant horsepower improvements
- Faster reed opening and closing for responsive engine operation
- Improved low-pressure and low-throttle response
- Greater intake velocity for enhanced engine performance
- Increased effective flow area
- Longer overall service life
- Designed to prevent engine damage if a reed breaks
- Fits 1981–1988 Yamaha PW50 models
- Fits 1984–1985 Yamaha YT60 Zinger models
- Brand: Boyesen
- Manufacturer part number: 674
- Vendor part number: 674
Fitment:
1981 Yamaha PW 50
1982 Yamaha PW 50
1983 Yamaha PW 50
1984 Yamaha PW 50
1984 Yamaha YT60 Zinger
1985 Yamaha PW 50
1985 Yamaha YT60 Zinger
1986 Yamaha PW 50
1987 Yamaha PW 50
1988 Yamaha PW 50
1989 Yamaha PW 50
1990 Yamaha PW 50
1991 Yamaha PW 50
1992 Yamaha PW 50
1993 Yamaha PW 50
1994 Yamaha PW 50
1995 Yamaha PW 50
1996 Yamaha PW 50
1997 Yamaha PW 50
1998 Yamaha PW 50
1999 Yamaha PW 50
2000 Yamaha PW 50
2001 Yamaha PW 50
2002 Yamaha PW 50
2003 Yamaha PW 50
2004 Yamaha PW 50
2005 Yamaha PW 50
2006 Yamaha PW 50
2007 Yamaha PW 50
2008 Yamaha PW 50
2009 Yamaha PW 50
2012 Yamaha PW 50
2013 Yamaha PW 50
2014 Yamaha PW 50
2015 Yamaha PW 50
2016 Yamaha PW 50
2017 Yamaha PW 50
2018 Yamaha PW 50
2019 Yamaha PW 50
2020 Yamaha PW 50
2021 Yamaha PW 50
2022 Yamaha PW 50
2023 Yamaha PW 50
2024 Yamaha PW 50