DAYUAN Petrol Engine Compression Tester Kit — Red Case, 3" Dual-Scale Gauge & Multi Adapters

DAYUAN Professional Petrol Engine Compression Tester Kit is a complete petrol engine compression testing set with a 3" dual-scale gauge, multiple threaded adapters, and quick-check rubber cones in a durable red case.

This compact kit gives you the fittings and readable gauge needed to measure cylinder compression on a wide range of petrol engines. The included 3-inch gauge displays both psi and bar for fast interpretation, and the stamped adapters cover common spark plug thread sizes so you can test many cars, motorcycles, ATVs, and small engines without buying extra parts.

How do I use the DAYUAN kit to test cylinder compression?

Testing with this kit is straightforward: remove the spark plug, attach the proper threaded adapter or rubber cone, crank the engine, and read the peak pressure on the gauge. The kit includes options for both threaded and non-threaded quick checks so you can choose the safest, fastest method for the engine you're working on.

• Choose the correct adapter: M10/M12/M14/M18 or 14mm/18mm spark plug sizes.
• Use rubber cones for quick, non-threaded checks on irregular ports.
• Crank engine to reach peak pressure and read 0–300 psi / 0–20 bar on the 3" gauge.

Which vehicles and engines will this compression tester work with?

The DAYUAN kit is built to cover most petrol engines that use common spark plug thread sizes and small-engine ports. It’s suited to light vehicles and small-displacement motors where the included adapters fit the plug hole or port geometry.

• Cars and light trucks with 14mm or 18mm spark plug access.
• Motorcycles, scooters, ATVs, and lawn equipment with M10–M18 threads.
• Small engines and custom applications using rubber cone checks.

What does the gauge read and how accurate is the display?

The 3-inch gauge has a dual-color scale showing 0–300 psi and 0–20 bar, providing clear readings for both imperial and metric users. The larger face improves legibility under garage lighting so you can capture peak readings reliably while cranking the engine.

• 3" face with dual scale: easy conversion between psi and bar.
• Clear color contrast on the dial for quick visual checks under working conditions.
• Robust construction designed to hold pressure during peak measurement.

What fittings and accessories are included in the set?

The kit is supplied in a sturdy red carrying case and includes threaded adapters with O-rings, two rubber cone ends for fast checks, and dedicated spark plug adapters so you can begin testing immediately. Fittings cover the most frequently encountered plug hole sizes.

• Threaded fittings: M10, M12, M14, M18 (male with O-ring).
• Spark plug adapters: 14mm and 18mm for direct plug-hole testing.
• Two rubber cone ends for non-threaded, quick compression checks.

Who is this for: Mechanics, DIYers, and small-engine technicians who need a versatile, portable compression tester capable of handling common petrol engines. If you work on cars, motorcycles, ATVs, lawnmowers, or other petrol-powered equipment and want a single kit that covers multiple thread sizes and provides a clear 0–300 psi readout, this DAYUAN tester set is designed to simplify diagnostics and routine maintenance.