DAYUAN Petrol Engine Compression Tester Kit — Red Case, 3" Gauge (0–300 psi/0–20 bar) with Adapters

DAYUAN Professional Petrol Engine Compression Tester Kit is a complete, portable set for measuring cylinder compression on petrol engines, delivered in a durable red carrying case.

This kit equips mechanics, home DIYers, and vehicle inspectors with the adapters and gauge needed to quickly assess engine cylinder health. The 3-inch analogue gauge shows both psi and bar for fast readings, while a selection of threaded fittings and rubber cone ends lets you work across a broad range of spark plug wells and shallow ports without extra tools.

How do I connect the tester to different spark plug sizes?

The kit includes multiple threaded fittings and spark plug adapters to fit a wide variety of petrol engines. Choose the matching male fitting or screw in a spark plug adapter to create a secure seal before cranking the engine for a compression reading.

• Fittings: M10, M12, M14, M18 (male with O-ring) for direct threads
• Includes 14mm and 18mm spark plug adapters for common plug diameters
• Threaded connections provide a tight seal to prevent pressure loss during testing

What if the spark plug hole is too shallow to thread an adapter?

For shallow or non-threaded openings the kit supplies two rubber cone ends that press-fit against the port for a fast preliminary check. They allow you to detect gross compression issues before committing to a threaded connection or removing parts.

• Two rubber cone ends for quick, non-threaded checks
• Useful for shallow spark plug wells or when threads are damaged
• Speeds up diagnosis when you need a rapid pass/fail assessment

How accurate is the gauge and what units does it show?

The included 3-inch dial features a dual-color scale with clear markings from 0–300 psi and 0–20 bar, suitable for most petrol engine compression ranges. The analogue display is easy to read while cranking, and the robust connection helps reduce leaks that could skew results.

• 3" gauge with 0–300 psi and 0–20 bar dual scale
• Large dial and color-coded zones for quick visual interpretation
• Sturdy mechanical design intended for workshop and roadside use

What fittings and extras are included in the kit?

The set comes organized in a red molded carrying case and contains a range of adapters, two rubber cone ends, and a gauge, allowing you to adapt to many petrol-engine configurations. Everything stores neatly so you can take the kit to jobs without losing small parts.

• Adapters for many spark plug types and depths
• 14mm and 18mm spark plug adapters included
• Two rubber cone ends for non-threaded checks
• M10, M12, M14, M18 male fittings with O-rings
• Red hard case for secure storage and transport

Who is this for: The DAYUAN petrol engine compression tester kit is built for professional mechanics, mobile technicians, automotive students, and experienced DIY enthusiasts who need a compact, versatile tool to diagnose cylinder sealing issues. It’s ideal when you require a dependable analogue gauge, multiple thread sizes, and quick-check options in one portable package without relying on vehicle-specific adapters.