The spark plug tester has two test holes, allowing you to test two spark plugs simultaneously. If you suspect a spark plug is malfunctioning, you can compare and test them to make an accurate assessment. This

adjustable dual-hole spark plug tester for cars

is used to test spark plug performance and ignition strength.

It is compatible with 12V gasoline engine spark plugs and can handle

input voltages from 100V to 240V.

The spark plug testing principle is as follows:

In an automotive ignition system, the high-voltage ignition coil generates a high voltage (10,000 volts or more). The spark plug diverts this voltage to the

high-voltage ignition coil in the cylinder. The spark between the spark plug electrodes ignites the fuel-air mixture. The JF109 can distinguish good spark plugs from bad ones by the strength of their spark.

Spark Plug Tester Operating Instructions:

1. Please turn off the power before inserting the spark plug.

2. The spark plug tester is a high-voltage detector, so do not touch the spark plug with your hand while it is operating to avoid any danger.

Spark Plug Tester Operating Instructions:

1. Place the spark plug in hole 1 or 2 of the tester; if you want to compare the new spark plug with the old one, place the new spark plug in hole 1 and the old one in hole 2.

2. Connect to the power supply.

3. Turn the key switch 4 clockwise to turn on the tester; indicator 3 will light up, and the tester is now operating at 1000 RPM.

4. Turn the key switch 4 clockwise again to adjust the operating frequency between 1000 RPM and 6000 RPM. The higher the frequency, the stronger the spark.

Contents:

1 spark plug tester,

1 power connector,