1993 Johnson Evinrude "ET" 90 degrees CV Service Manual, P/N 508285, Page 62Get this manual
Pulse Limiter Fitting
f51 The pulse limiter fitting for the VRO pulse hose has an integral
check valveThe check valve is not serviced separately, but must be clear to allow normal pump operationA clogged check valve will limit fuel and oil supply, causing serious powerhead damage
1Remove the pulse limiter fitting from the crankcasef612Backflush the valve with mild aerosol solvent to remove any carbon deposits
rr:i=J If you find excessive carbon deposits, check the engine for
causes of backfiring: Linkage adjustments incorrect Engine temperature incorrect Crankcase air leaks Carburetor problems Extended use of flushing attachment
3Clean the threaded portion of the fitting and apply OMC Pipe Sealant with TeflonInstall the fitting, and secure the pulse hose with clampPump For function tests of the System, this sectionpump, refer to Testing Fuel