Sea-Doo 1503 1630 Rotax 4-TEC. High performance valve spring, Titanium retainer and steel spring seat to suit the 232- series of Kelford Racing Cams. Supplied spring seat fits on top of OEM seat to give seat pressure of 85lb at 33.75mm installed height. 179lb at 11.0mm valve lift. Coil bind at 20.85mm. 10,000rpm capable.