1997 Johnson Evinrude "EU" 40 thru 55 2-Cylinder Service Manual, P/N 507265, Page 84Get this manual
Pulse Limiter Fitting
The pulse limiter fitting for the VRO pulse hose has an integral check valveThe check valve is not serviced separately, but it must be clear to allow normal pump operation
Noteclogged check valve will limit fuel and oil supply, causing serious powerhead damage1Remove the pulse limiter fitting from the crankcase
rn 2Backflush the valve with OMC Carburetor and Choke Cleaner to remove any carbon depositsINotel 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 Teflon4Install the fittingSecure the pulse hose with ratchet clampPump