Re: Timing Questions
0 = Top Dead Center<br />ATDC = After Top Dead Center (retarded)<br />BTDC = Before Top Dead Center (advanced)<br />2 ATDC to 6 BTDC is an 8 degree tolerance.<br />Place the flywheel at 0 (TDC). The markings to the right are ATDC, the markings to the left are BTDC.<br /><br />2-strokes fire twice as often as 4-strokes. Divide RPMs by half.<br /><br />Timing is done with the motor not running. You'll need a starter switch and a spark tester. You can put the plugs in the caps and tape them to the block or something if you don't have spark tester(s). You need spark for the timing light to flash. Disconnect the throttle cable to manipulate the throttle lever by hand. Turn the key on or you won't get spark (can't tell you how many times I forget). Then turn the motor over with the starter switch. You can have an assistant man the key if you don't have a starter switch. Follow the procedures in the manual and make sure you get the WOT (wide open throttle) timing right. It would be a good idea to check the timing once the boat is on the water for the best accuracy, but bouncing around at WOT isn't usually very safe. That's why the static method is preferred.<br /><br />I have run into one timing light that didn't like to work right on 2-strokes. It was a Snap-On. I don't recall the model. It would flash too often and never on time. Worked fine on 4-strokes. So if the thing flashes wacky, it could be the light. That one had RPMs and an advance knob. I think that's what was freaking out the light. Never had that problem with no-frills lights, myself.
