Pretty much any of the crossflow V4s from about 1980 on up (which includes the 88SPL) were good motors. As with any used outboard, maintenance is everything - it may have been a good motor off the assembly line, but abuse and lack of care can kill any motor. Check compression, check lower unit oil, check overall appearance. A motor that LOOKS like it's been taken care of probably has been taken care of. Post 1980 motors have the better CD ignition, low-ring pistons, later style power trim (if it has trim), better idle circuits in the carbs, straight mechanical lower units (no electric or hydraulic), and older cowlings will fit them if you want a retro look.
I have a 1983 Johnson 90 that I rebuilt when I bought it four years ago and it's been a solid runner. Actually not terrible on gas if I go easy on the throttle. I run a 1976 cowling on mine to make it match my '76 boat.
This is critical with any of the crossflow V4s - prop them to hit peak RPM between 5500 and 6000 RPM. I propped mine to hit 5800 with just me in the boat. They actually run COOLER if they're propped for that range. Any less than 5500 is lugging the engine and you run the risk of coking the piston rings and sticking a piston, particularly with today's gas.
- Scott