Compatibility with 14mm Colortune and Hi-Gauge

The Gunson G4055A adapter is specially designed to let you use your 14mm Colortune spark plug or Hi-Gauge compression tester on engines with 10mm spark plugs. This allows for accurate measurements on a wider range of vehicles, including classic motorcycles and two-stroke engines.

Easy installation

The set includes:

• 1 x 14mm to 10mm thread adapter
• 1 x soft copper sealing ring

Installation is simple: screw the adapter with the supplied copper ring into the 10mm spark plug hole. Then attach the 14mm Colortune or Hi-Gauge compression tester to the adapter using the standard copper ring. The adapter can be tightened with a 19mm or 3/4" spanner.

Wide applicability

This adapter is suitable for:

• Classic motorcycles
• Two-stroke engines
• Modern and classic cars with 10mm spark plugs

Note: this adapter is only compatible with the 14mm Colortune and Hi-Gauge compression testers and does not fit the 10mm or 12mm versions.

Durable and reliable

The Gunson G4055A is made from high-quality materials and comes with a soft copper sealing ring for optimal sealing and reliable performance.

Alternative sizes available

For other spark plug sizes, Gunson offers the following adapters:

• G4055B: 12mm adapter
• G4055C: 14mm tapered adapter
• G4055D: 14mm long adapter
• G4055E: 18mm adapter

With the Gunson G4055A adapter, you expand the functionality of your Colortune or Hi-Gauge compression tester, allowing you to make accurate diagnoses on engines with 10mm spark plugs.