![Valve spring hard (2 pieces_ Valve spring hard (2 pieces_](https://www.beneduracing.com/2088-large_default/valve-spring-hard-2-pieces-gx390-benedu-racing-for-all-your-kart-parts.jpg)
Reference: shspeed
Reference: shspeed
Additional inner spring set (set = 2 pieces)
These valve springs are inserted into the original and strengthen them.
These springs are suitable for engines which have been easily machined (e.g., RPM controllers removed).
Reference: 1736
Reference: 390-ROLLRCKS-13
Reference: 1691
Reference: 1516
Reference: 1663
Reference: 2210