1979 merc in line 6 90 hp tune up

[keymanrick]

What is the proper way to time a 1979 merc 6cyl 90hp? should I use a timing light or dial indicator? my selock has everything but the 1979
Thanks

 

[Moody Blue]

Re: 1979 merc in line 6 90 hp tune up

Take a look in the FAQ section for an excellent post on the sync and link procedure. Easy to follow and sets things up as they should be.

 

[Chris1956]

Re: 1979 merc in line 6 90 hp tune up

Rick, Merc had two different ignition systems. A distributor ignition with one coil and an ADI ignition with six coils. Figure out which one you have, and perform the correct procedure. Your Seloc should have both procedures.

You still need to set the timing pointer or verify it is correct. I use a caliper thru # 1 plug hole. Set motor at TDC using a screwdriver. Use caliper to measure from plug hole to top of piston. Add .464 inches to this measurement, and dial it in on caliper. Back off piston, and insert caliper into plug hole. Gently bring piston to touch caliper. Note where timing pointer points to. adjust to the .464 BTDC mark on the timing decal.

Now use timing light to set idle pickup timing and max spark advance.