Here is a link to MarineEngine.com web site where you can purchase a complete Force/Sears 25 hp power head for $250.00 plus shipping.

http://www.marineengine.com/newparts...R800-819240A+6

Here is the part # for this assembly.
800-819240A 6 - POWERHEAD, 25HP 1996 TO 1998 Force & Sears