Ignition Systems Flashcards
what are the four types of spark plug fowling
lead
carbon
oil
graphite
when are cold plug used
high temperatures, high compression with a turbo
when are hot plugs used
low temp, low compression without a turbo
why are ignition leads insulated
to prevent radio interference
where does a spark plug fire when the engine is running
20 degrees before top dead center
why does the spark plug fire later on start-up
because if it fires before top dead center there is a chance it will force the piston in the wrong direction
what are the main components of a spark plug
electrodes (Center and ground) resistor glass seal terminal contact ceramic insulator shell
what are the who main terminal end sizes? which is most common
5/8-24 and 3/4-20.
3/4-20 is most common
what are the two electrode types for spark plugs
massive and fine wire
why are spark plugs placed in numbered trays during servicing
condition of the plugs reveals much about condition of the cylinder it came from
when is a spark plug electrode considered to be worn out
when it is half of its original thickness
excessive oil in plugs indicates what
worn or faulty piston rings and valve guides or the engine is still in break in period
what is the difference between low and high tension ignition systems
Low tension - Magneto only has 1 winding. transformers are located at the spark plugs and contain a secondary winding. outdated
High tension - primary and secondary coils are both located within magneto and there are no transformers. simpler
main components of a magneto
housing rotating magnet distributor gear point assembly distributor block condenser/capacitor
what is an impulse coupling used for
used to fire spark plugs during engine start up
