Dalton Secondary Spring for BRP
Yellow / Grey
If having problems with engine speed drifting more than 400 rpms at top end with a 180/300, 200/300, 218/300 secondary spring - then this spring is a good remedy to add forces in to reduce engine speed loss. (at high vehicle speeds)
Say you had correct engine speed up to 4/5''th of your top speed and the engine speed was drifting low by 400~500.  Changing from xxx/300 to xxx/335 will add enough spring force into the system to not allow the engine speed to drop more than 100~200.