1988 Johnson Evinrude "CC" 9.9 thru 30 Service Manual, P/N 507660, Page 97Get this manual
Disassembly
1 0 1Remove primer pump housing retainer from primer Ipump[!2] 2Remove primer plunger from housing Discard O-ringsCleaning, Inspection and Repair Inspect brass plunger shaft for any burrs or scratchesRemove small scratches by polishing the plunger with crocus clothIf the plunger has deep scratches, replace the plungerInspect plunger where cross hole intersects inside holeAny burrs around cross hole will accelerate wear of O-ringsRemove any protruding burrs and polish with crocus clothThe check valve under the small nipple on the primer pump housing allows fuel flow out of the pump housing and prevents flow into the housing To inspect for proper check valve function, use squeeze bottle containing alcohol (such as isopropyl rubbing alcohol)Connect clear plastic hose between small nipple and bottle to observe flow of alcoholSqueeze the bottle lightly to force alcohol through the hoseVisually check for flow of alcohol into the housing It is permissible for few drops to be presentThis indicates the check valve is blocking the flow and functioning correctly If steady stream of alcohol flows through the small nipple, the check valve is inoperative and the primer pump housing must be replacedInstall hose over the large nipple of the primer pump housing and connect other end of hose to the alcohol squeeze bottlePlace your thumb over end of the plunger housingSqueeze the alcohol bottle to fill the plunger housing Alcohol should flow freely out of the small nipple, indicating no obstructionsIf no flow is indicated, replace primer pump housing