1999 Volvo Penta "WT" Models Workshop Manual, Page 274Get this manual
Several different types of equipment are available for reseating valve seats; the recommendations of the manufacturer of the equipment being used should be carefully followed to attain proper resultsRegardless of what type of equipment is used, however, it is essential that valve guides be free from carbon or dirt to ensure proper centering of pilot in the guidea.lnstall expanding pilot in the valve guide bore and expand pilot by tightening nut on top of pilotbPlace roughing stone or forming stone over pilot and just clean up the valve seatUse 46 stone for both the inlet and exhaust valve seatscRemove roughing stone or forming stone from pilot, install finishing stone on pilot and cut just enough metal from the seat to provide smooth finishdNarrow down the valve seats to the proper width for the intake and exhaustSee Specifications at the end of this section INotel
This operation is done by grinding the port side with 30 stone to lower seat and 60 stone to raise seatmINotel