Piaggio 438027 Spark Plug Champion RG4HC – Vespa, Beverly, Scarabeo, and Runner 4T 50-250 cc

The original Piaggio 438027 spark plug is the Champion RG4HC, the original equipment spark plug for the Piaggio Group's four-stroke engines: Vespa ET4 and Granturismo, Beverly, X8, X9, X Evo, Carnaby, MP3, Liberty, Fly, Zip, Gilera Runner and Nexus, Aprilia Scarabeo, Atlantic, Sport City, Mojito, RS4, and Tuono. Thread Ø 10 mm, 19 mm long, 16 mm hex, resistive. Product code 438027.

✓ Strengths

• It is the original equipment spark plug – code 438027 is the one specified by the official Piaggio parts catalog for all these engines, not just a cross-reference match.
• Resistive – the initial "R" in RG4HC: shielded against electromagnetic interference, as required for engines managed by an ECU.
• Champion Copper Plus series – copper core and nickel alloy electrode, the classic construction for service spark plugs.
• One code for four brands – Piaggio, Vespa, Gilera, and Aprilia: the same part covers dozens of models from 50cc 4T up to 250cc.
• It costs just a few euros and is the first thing to change when the engine is hard to start, idles poorly, or stutters during acceleration.
• In its sealed Champion box, new and never fitted.

Technical specifications

Vehicle compatibility

The list is taken from the official Piaggio and Aprilia parts catalog (B2B area), family by family. If your vehicle is not in the table, or if you have a specific trim, send us the VIN and we will verify the correct code before you order.

Who it is perfect for

It is the part for those who do their own maintenance and want to use the right spark plug, not an equivalent chosen by eye from a conversion table. It is useful for those who have a four-stroke scooter that is hard to start after the winter, idles poorly, or loses brightness in acceleration: the spark plug costs a few euros and is the first thing to rule out before looking elsewhere. It is also the spark plug to keep as a spare under the seat, because the same code fits almost the entire Piaggio, Vespa, Gilera, and Aprilia four-stroke range from 50cc to 250cc, and it does not expire in the drawer.

Frequently asked questions

On which scooters is the 438027 spark plug fitted?
It fits on the Piaggio Group's four-stroke engines: Vespa ET4 and Granturismo, Beverly, Carnaby, X8, X9, X Evo, MP3, Liberty, Fly, Zip 100, Gilera Runner 4T and Nexus, Aprilia Scarabeo, Atlantic, Sport City, Mojito, RS4, RX, SX, and Tuono 125. The table above shows the years and versions of each family.

Is it suitable for my two-stroke Zip or Runner?
No. The 438027 is the spark plug for four-stroke engines. For two-stroke engines — Zip 2T, NRG, Typhoon 2T, Runner 2T — the catalog specifies a different spark plug with a different thermal rating. If you are not sure which engine your vehicle has, write us your VIN.

What does RG4HC mean and where can I find it written?
RG4HC is the Champion code for the spark plug, printed in black on the white insulator: the "R" indicates that it is resistive, i.e., shielded against electromagnetic interference. Champion also lists it with the OE number 092. The corresponding Piaggio code is 438027.

Can I fit an equivalent NGK?
Conversion tables indicate the NGK CR9E as the equivalent of the Champion RG4HC. It is an indicative correspondence: for your engine, the manufacturer's specified spark plug remains the 438027, and for a part that costs a few euros, it is better to stick with the original.

How many spark plugs do I need and what wrench should I use?
Only one: all the engines in the table are single-cylinder. The price indicated refers to a single piece. To remove and replace it, you need a 16 mm spark plug wrench; work with a cold engine and tighten without overdoing it, because it has a flat seat with a gasket.