Tune-up Procedures

[jmcgill89]

I finally got an OMC Manual for my '77 Evinrude 85hp. It's amazing how much more that book covers as opposed to the Seloc manual.<br /><br />That being said, I want to perform a full tune-up on my motor. I think I understand OMC's procedure for synchronizing the carbs and linkage, but I'm a bit in the dark about how to do the timing procedures. I'm pretty sure that my carbs need to be adjusted....the lower throttle does not look like its opening all the way, as I can still open it further by hand when the top one is wide open.<br /><br />As for the timing....I don't have the ability to run the motor in a test tank or on a "wheel" (whatever that is) to set the timing. I was thinking of doing what Joe Reeves recommends to try to get it close, but I don't know how to use a timing light or a spark tester, etc.<br /><br />Can anyone give me some quick tips on how to do this?<br /><br />Thanks,<br /><br />Joe

 

[angus63]

Re: Tune-up Procedures

Be aware that some carbs will open past horizontal. Eyeball the throttle flaps that they are all fully closed at idle (I mean fully, makes a big difference if slightly open), and that they all begin to open at the same time as you give it throttle, and finally that they all become horizontal when fully open. If you are not comfortable following the manual or Joe's method, I suggest finding someone who is in order to be assured of your settings. A mistimed motor is a rebuild waiting to happen.<br />Good Luck

 

[ED21]

Re: Tune-up Procedures

A spark tester is used so that you don't burn out electronics when the spark plugs are pulled.<br />I cheated a bit & left the spark plugs plugged into the boot & then wrapped wire around the base of each plug & then grounded them to engine.<br />Buy or borrow a inductive timing light, clip the sensor wire to #1 plug wire & attach power wires to battery.<br />Point the light at the flywheel & see where the timing mark is when cranking the engine.<br />Adjust as required per the manual & as compensated by Joe Reeves recommendation.<br />I did it his way & it seems to be fine. <br />I would like to test it while running, but that is next to impossible for me.