BETOOLL compression tester kit 9-piece Petrol 0–300 PSI gauge with 32-blade feeler for engine diagnostics

The BETOOLL 9-piece petrol engine compression tester kit is a complete diagnostic set for checking cylinder compression and spark plug gaps on petrol engines up to 300 PSI.

This compact kit bundles a triple-range compression gauge, four adapters, a one-handed release valve and a 32-blade steel feeler gauge so you can quickly assess engine health. Designed for petrol engines (not crude oil engines), the gauge displays readings in psi, bar and kg/cm², while the feeler blades are laser-etched for clear metric measurement. Whether troubleshooting a misfire, prepping a used engine for sale, or tuning performance, this kit gives straightforward, repeatable measurements.

How do I use the compression tester to diagnose cylinder problems?

Remove the spark plug, thread the correct adapter into the plug hole, then crank the engine several times while watching the gauge. Repeat the test three times per cylinder to confirm consistent readings and compare cylinders for variance. Low or widely varying compression between cylinders indicates potential issues like worn rings, valve leaks, or head gasket failure.

• Remove spark plug and attach matching adapter
• Crank engine 4–6 compression strokes per test
• Record three readings per cylinder for accuracy
• Compare cylinder readings to manufacturer specs

What does the triple-range gauge show and why does it matter?

The gauge gives readings in 0–300 psi, 0–20 bar and 0–21 kg/cm² so you can read results in the unit you prefer. A wide range covers small engines up to car and light-truck petrol engines, eliminating guesswork from conversions. Clear graduations let you spot marginal compression that might not be obvious with a single-scale gauge.

• 0–300 psi range for common petrol engines
• Dual metric scales for international use
• Easy-to-read dial for quick diagnostics
• Works across small engines to automotive cylinders

How does the feeler gauge and release valve improve testing and tuning?

The included 32-blade steel feeler gauge helps set or verify spark plug gaps accurately while the compression tester's release valve allows single-handed pressure bleed-off. Laser-etched sizes on the blades ensure long-term readability and reliable gap measurement. Together they let you diagnose compression faults and adjust ignition components without switching tools.

• 32 laser-etched steel blades for precise spark plug gaps
• Release valve enables controlled, one-handed pressure release
• Durable construction suited for workshop or field use
• Compact kit keeps diagnostic tools organized

Who this kit is for: the BETOOLL 9pcs compression tester is intended for mechanics, vehicle DIYers, small-engine technicians and anyone who services petrol engines on cars, ATVs, boats, lawn mowers or light trucks. It’s ideal when you need fast, repeatable compression checks and accurate spark plug gap measurements without carrying a large toolset. Note: not designed for crude oil engines or specialized heavy industrial engines.