My quest continues to determine the interchangeable parts between a 1997 & 2000 vintage merc 40 & 50 Hp engines. While checking the Merc web site, I note that the 40HP/50HP/60HP motors all have the same Bore X Stoke. Can anyone suggest how the increase in HP is achieved between these models?<br /><br />Thank You in advance....<br /><br />Rcb
