I have a v4 90 hp. 1984. Only when it is in gear, thier is a clunking sound every 30 seconds or so. It almost sounds

Hi, You could have a cable adjustment problem or a gearcase problem but lets try adjustment first.Where the cables come through the front of the motor pan the cables have an adjustment trunnion. The shift is on the bottom loosen the cable trunnion retainer. Remove the nut on the end of the cable manually shift the engine into neutral then adjust the cable so it slips on to the stud freely. Reassemble check shift put in forward turn prop so it locks if not turn the trunnion to the right till prop locks check reverse if it doesn't lock adjust trunnion to the left till locks. Then check shift if doesn't lock in forward or reverse leave cable disconnected put boat in the water and shift manually, if shifts ok we need to check control cables and control box. If doesn't shift manually you have a gearcase problem. Thanks click "Accept" button. Post back with questions..Tan