???--IT IS A 1992 MODEL !!------Use the 1992 parts book.-----There is no difference between a commercial model and a recreational model.---Well , maybe paint and decals that you can clearly see !
I say it is a 1992 model -----Commercial model.----Most know that in 1993 there was a total redesign of the 9.9 / 15 HP models.-----Cowlings were different.----Recoil was mounted on top of flywheel.------The RPLO is clearly listed as a 1992 model !!
Some will argue.----I would charge the battery.----Then have battery load tested ( even if new ) last week.-----Then take starter apart for inspection .----Test ohms on armature.----No money spent on these tests !
I am well aware of how much it takes to drive a boat at 40 MPH !!!----Point is folks drain out very good gear oil on the outdrive and rarely even check rear axle on the pick-up truck !
Agreed with 20 hrs a season gear oil can be used for many seasons.-----After all many rear axles in pick-up trucks rarely get oil changed for years and years..----If there is no water in the gear oil it is good for another season.
Did you clean carburetors ???----Did you install latest water pump kit with instruction to move tell tale fitting to top of block.----And other cooling modifications , yes or no ?