Re: timing lights
With the advance timing lights you can set them so they go off a number of degrees off when the spark goes. For example, say the engine sparks at 20 degrees before top dead center. If you set the timing light with 20 degrees of advance, you'll see the timing pointer pointing right at the TDC mark.<br /><br />Normally that's used the other way, so you turn the knob on it until you read TDC, and then note that the spark is 20 degrees before that by the position of the knob.<br /><br />Normally all modern timing lights, advance ones included, are coupled inductively. This means you just clip a pickup over top of the plug wire rather than making a direct connection.<br /><br />I don't know of any outboard that requires an advance timing light. I guess it's useful on some cars. Some timing lights don't work well with an outboard's CDI or magneto ignition so get one you can return if it doesn't work out. It seems to be hit-n-miss: some expensive ones don't work at all and some cheap ones work just fine.
