2003 Polaris ATV Trail Boss 330 Factory Service Manual, Page 64Get this manual
ENGINE 4Follow the manufacturers instructions provided with the valve seat cutters in the Valve Seat Reconditioning Kit (PN 2200634)Abrasive stone seat reconditioning equipment can also be usedKeep valves in order with their respective seatNOTE: Valve seat width and point of contact on the valve face is very important for proper sealingThe valve must contact the valve seat over the entire circumference of the seat, and the seat must be the proper width all the way aroundIf the seat is uneven, compression leakage will resultIf the seat is too wide, seat pressure is reduced, causing carbon accumulation and possible compression lossIf the seat is too narrow, heat transfer from valve to seat is reduced and the valve may overheat and warp, resulting in burnt valves5Once thoroughly heated, place cylinder head on blocks of wood which will allow the old guides to be removed6Using valve guide driver, drive guides out of the cylinder head from the combustion chamber sideBe careful not to damage guide bore or valve seat when removing guides7Place cylinder head on cylinder head tableNOTE: Be sure cylinder head is still at 212 (100 C) before installing new guides8Place new guide in the valve guide installation tool and press guide in to proper depthCheck height of each guide above the cylinder head (A)Refer to specificationsNOTE: The guide can also be driven in to the proper depthInspect the guide closely for cracks or damage if driver is usedReaming The Valve Guide 9Allow cylinder head to cool to room temperatureApply cutting oil to the reamerGuides should be reamed from the valve spring side of the cylinder headReam each guide to size by turning the reamer clockwise continuallyContinue to rotate reamer clockwise during removal of the tool