Is Advance timing before TDC?
“Timing advance” refers to the number of degrees before top dead center (BTDC) that the spark will ignite the air-fuel mixture in the combustion chamber at the end of the compression stroke. Igniting the mixture before the piston reaches TDC will allow the mixture to fully burn soon after the piston reaches TDC.
What is normal ignition timing advance?
That is typically 15-35 degrees before TDC (top dead center) of the power stroke depending on the engine speed. Best power is achieved when ignition timing is set to fire the spark ahead of time to reach that peak pressure at about 2 degrees after TDC.
Where is the advance timing mark on a Harley Davidson?
Aim timing light into timing inspection hole. Front cylinder advance timing mark should be centered in timing inspection hole. If not, see ADJUSTMENT below. 6. Set engine slow idle speed as described in Step 4 with engine running at normal operating temperature and with enrichener control knob pushed in fully.
Where do I find the timing mark on my engine?
See Figure 1. Locate the proper timing marks for your engine. If the shop manual is not available, remove spark plugs, turn engine until front piston is at TDC on compression stroke and identify TDC mark on the flywheel. 2. Connect leads of INDUCTIVE TIMING LIGHT to front spark plug cable, to battery positive terminal and to ground. 3.
What does it mean to advance ignition timing?
Advancing your ignition timing means that the spark plug fires the air-fuel mixture in the cylinder earlier (measured in degrees Before Top Dead Centre) than it does out of the factory.
When to put engine in or out of TDC?
If the crankshaft pulley bolt needs to be removed or it is important that the engine remain at the TDC position, you’ll need to install the “engine in” flywheel lock (9206). There is also an “engine out” flywheel lock (9130) which is used if the engine is on an engine stand.