Engine Rebuild.

1986 and UP   70HP  OMC     increase main jet one size.                      

1989 and UP   60HP  OMC     increase main jet one size. 

V4 and V6 Crossflow  OMC   set Ignition timing at 24 degrees instead of 28.

1985-92 V6 Looper  OMC   install #65 main jets in engine with #62 main jets.

all V6 increase main jet by .002                                                

all V6 retard timing 2 degrees from original spec.             

Mercury Outboard, 1987 and up 3 cylinder, 70-90HP, increase main jet by .002

Mercury Outboard, 1987 and up 47 cylinder, 100-125HP, increase main jet by .002

Mercury Outboard V6 EFI, verify fuel pressure. Minimum, of 39 psi

Chrysler/force 3 and 4 cylinder engines, retard timing to 28 degrees instead of 32