Gasoline Engine Timing
Gasoline engines have only two possibilities for their ignition, electronic or magnito. The magnito ignition timing is factory set and has virtually no adjustment. It's typacally set around 26 to 30 degrees. Electronic ignition is actually an aftermarket item and is adjustable. The adjustment varies with the engine-maker since they make the adapters for their specific engine. Regardless of how the mechanical portion is made, the actual ignition point is the same.
Most engines using unleaded gas will time between 26 to 34 degrees. A few "hotter" engines using high octane will time up to 36 degrees. Methanol burning engines will time as high as 38 degrees and on rare occasions go as high as 40 degrees when idling isn't needed.
The very first thing required for accurate timing is to know exactly where TDC (Top Dead Center) is. The second item needed is a way to index (in degrees) the rotation of the crankshaft. The last thing required is in fact, a good functioning ignition.
Let's assume your ignition is working, by that I mean it sparks relaibly. So let's proceed to go through the sequence to properly get your timing right...
#1: finding TDC
#2: rotation degrees
#3: time it
A lot of things go into determining where the timing ought to be for each engine. The ideal way to determine this is to time it while it's running. But most engines won't allow this. So, you will have to set it and take some RPM readings as well as observing the throttle-up accelleration. A very good starting point is +28 degrees. This is a safe and reliable point for most engines.
Make adjustments in very small increments around 2 degees or so. When you're done lock everything down TIGHT.
* * * Electronic VS. Magnito * * *
PROS to Magnito
CONS to Magnito
PROS of Electronic
CONS of Electronic