Re: whats the exact year??
Early 70's is correct. Without the model number it can't be pinpointed any closer than that. They had red stripes for a number of years.
That era Mercs could be tricky. They have multiple carbs and if not perfectly adjusted they would grenade the top cylinder. If the motor is low hours, the price is right. To be made reliable it woul;d need a real good Merc mechanic to recondition it. That includs, carbs, water pump, tune-up etc.