Timing adjustment question

[nenikol23]

Does somebody have a DIY on the step by step process to perform a timing adjustment on a 240 EFI ?
I have the manual, however I believe my lack of knowledge in timing procedures and the use of timing lights leads me to a brick wall.

 

[Tim75]

I was told by an old dealer that among other things needed to set timing, is a dealer-only electronic box called an idle stabiliser. Not available to the public.

Tools needed: 1 inch travel indicator, spark plug thread adapter, timing light, voltmeter, tps harness, Mercury DDT & cable. The service book never mentions the idle stabiliiser.

Since you can toast an engine by changing the timing, be VERY careful.

 

[poppie]

Did mine just fine using just a timing light and volt meter with the procedure in the manual. I skipped setting the top dead center minus the .462" step since the pointer on the flywheel cover wouldn't have ever been moved. Remove all the plugs accept for #1 and start at the throttle cam adjustment step. Make sure your battery is fully charged and disconnect all the wires it tells you to. These steps are important! You will need a helper to turn the key over for you when using the timing light. Once the idle timing and maximum spark advance is set, adjust the tps using the volt meter method in the manual. Again, unplugging the wires it says to is important. Once you feel you have it set, take the boat to the ramp. Leave it strapped down to the trailer and verify your setup under load.