1984-1986 Mercury Force 4HP Outboards Service Manual, Page 28Get this manual
Poor Perform_nee PROBLEM POSSIBLE CAUSE
Note: Check for fuel related causes firstWHAT TO DO
Weak yellowish or red spark
Poor groundsDamaged or worn high tension leadMalfunctioning stop switch
Check groundsReplaceDisconnect leads from stop switch and repeat testIf defectivereplaceAdj ust points
Points not ad justed propertytoo wide or too narrowPoints pitted or burnedPoorly grounded or defective top crankshaft seal Points oily or greasyExcess lubrication of cam wick or contamination due to defective top crankshaft sealWeak or defective condenser