Re: 85 hp evinrude 1975
Make sure the butterflies on the carbs are open all the way and the timing linkage is up against the stop at wot. You can do this of course with the engine off at home.<br />Have you checked your timing at wot? <br />Here is a method of checking your timing at home.<br />_________________________________________________<br /><br />(Timing At Cranking Speed 4°)<br />(J. Reeves)<br />The full spark advance can be adjusted without have the engine running at near full throttle as follows. <br /><br />To set the timing on that engine, have the s/plugs out, and have the throttle at full, set that timer base under the flywheel tight against the rubber stop on the end of the full spark timer advance stop screw (wire it against that stop if necessary). <br /><br />Rig a spark tester and have the gap set to 7/16". Hook up the timing light to the #1 plug wire. Crank the engine over and set the spark advance to 4° less than what the engine calls for. <br /><br />I don't know the full spark advance setting your engine calls for, but to pick a figure, say your engine calls for 28°, set the timing at 24°. The reasoning for the 4° difference is that when the engine is actually running, due to the nature of the solid state ignition componets, the engine gains the extra 4°. <br /><br />If you set the engine to its true setting at cranking speed, when running it will advance beyond its limit by 4° which will set up pre-ignition causing guaranteed piston damage! You don't want that to take place. <br /><br />No need to be concerned about the idle timing as that will take care of itself. The main concern is the full advance setting<br />_________________________________________________<br /><br />After you check it this way you need to verify it on the water do this by backing the boat into the lake, but leave it on the trailor. You will need two people. Hook up the timing light and have somebody start the engine and shift it into gear at wot, and check the timing again.
