If the correct OEM part number is known it is easy to convert to a Sierra number using the utility above.

Example:  A water pump repair kit for a 40 hp yamaha OEM part number 63D-W0078-01 inserted into the OEM/Competitive Part # contains
will result in a Sierra part number of
18-3415IMPORTANT - To use this number on Southside Marine Components online store -  this number must be preceeded by an S - ie. S18-3415

SEE IMAGE BELOW
SONAR PARTS UTILITY