Re: force 85 tilt
I would be surprised if your motor is bad but the valve body is good. That is possible but not very likely. On that particular year the motor is more durable than valve body (on 88-92 it's about same).
Anyway ...
if it is in freshwater condition then you can get motor rebuilt for $70-$150, swap entire pump assy. (motor + valve body) for rebuilt @ $220-$290, or buy a brand new motor for $230-$280. It depends upon quality of rebuild, condition of motor, and model being replaced/rebuilt. Iboats, E-bay, and google are my favorite places to look.
Force three wire motors are designed to be directly wired to your switch. Force relays are designed for 2 wire systems and won't work with your 3w motor.