1997 Johnsoon Evinrude "EU" 50 thru 70 3-Cylinder Service Manual, P/N 507266, Page 83Get this manual
Inspection
1Inspect brass plunger shaft for any burrs or scratchesRemove small scratches by polishing the plunger with crocus clothIf the plunger has deep scratches, replace the plunger2Inspect plunger where cross hole intersects inside holeAny burrs around cross hole will accelerate wear of a-ringsRemove any protruding burrs and polish with crocus cloth3The check valve under the small nipple on the primer pump housing allows fuel flow out of the pump housing and prevents flow into the housing29281
[] 4To check valve function, use small syringe filled with isopropyl alcoholConnect clear plastic hose between small nipple and syringe to observe flow of alcoholSqueeze the syringe lightly to force alcohol through the hoseVisually check for flow of alcohol into the housingIt is permissible for few drops to be presentThis indicates the check valve is blocking the flow and functioning correctlyIf steady stream of alcohol flows through the small nipple, the check valve is inoperative and the primer pump housing must be replaced[] 5Install hose between the large nipple ofthe primer pump housing and the syringePlace your thumb over end of the plunger housingSqueeze the syringe to fill the plunger housingAlcohol should flow freely out of the small nipple, indicating no obstructionsIf no flow is indicated, replace primer pump housing Assembly