Piaggio 293845 Shielded Spark Plug Cap Ø 4 mm 5 kΩ – Beverly, X9, Nexus, ET4

The Piaggio 293845 shielded spark plug cap is the original connector (pipette) that attaches the high-voltage cable to the spark plug. "Shielded" means it incorporates a 5 kΩ resistor: this is used to suppress electromagnetic interference generated by the spark, which would otherwise confuse the ECU, immobilizer, and digital dashboard. On a modern scooter, this is no minor detail: a cap with an out-of-spec resistance or oxidized contact causes hard starting, unstable idling, hesitation during acceleration, and in the worst cases, warning lights and erratic readings on the dashboard. It is the replacement part specified by the manufacturer for a huge portion of the Piaggio Group's production: Beverly, X9, X Evo, MP3, Carnaby, Nexus, Runner 4T, Atlantic, Sport City, Scarabeo, and Vespa ET4.

✓ Key features

• Original Piaggio spare part — manufacturer code 293845, official designation "SHIELDED CAP"
• Built-in 5 kΩ resistor — interference suppression, as required by electronic control units
• 4 mm Ø connector, the standard size for Piaggio Group high-voltage cables
• Huge coverage — a single part number for Piaggio, Aprilia, Gilera, Vespa, and Scarabeo, from 125cc to 500cc
• Fresh contact — eliminates oxidation that causes spark loss without giving obvious symptoms
• Easy installation — screws onto the existing cable, no special tools required

Technical specifications

Vehicle compatibility

List drawn from the official Piaggio spare parts catalog (B2B). Families are grouped with the production years covered.

Who it's perfect for

• Anyone with hard starting or unstable idling who has already checked the spark plug and battery
• Workshops and service centers working on Piaggio Group maxi-scooters that want the most common cap always in stock
• Anyone performing preventive maintenance and replacing the cap along with the spark plug and cable during major services
• Anyone whose digital instrumentation is giving odd readings while the engine is running: a non-shielded or degraded cap is a classic cause

Frequently Asked Questions

What is the Piaggio 293845 shielded spark plug cap?
It is the original connector that attaches the high-voltage cable to the spark plug, referred to in the Piaggio catalog as a "shielded cap." It integrates a 5 kΩ resistor that suppresses electromagnetic interference from the spark and has a 4 mm diameter cable connection.

What does "shielded" mean?
It means the cap contains a resistor (5 kΩ here) that attenuates radio interference generated by the spark discharge. It serves to protect the ECU, immobilizer, and digital instrumentation: on fuel-injected vehicles, a cap without a resistor can cause electronic malfunctions.

How do I know if the cap needs replacing?
Typical symptoms include hard cold starts, unstable idling, hesitation during acceleration, and increased fuel consumption. Upon removing it, you often see green oxidation on the internal contact, cracks in the rubber, or blackish discharge traces on the external surface.

Which scooters does it fit?
The official Piaggio catalog lists it for a very wide range: Piaggio Beverly, Carnaby, MP3, X7, X8, X9, and X Evo, Gilera Nexus, Runner 4T, and Fuoco 500, Aprilia Atlantic, Mojito, Sport City, and SR MAX, Scarabeo with Piaggio engine, and Vespa ET4 125 and 150.

Can I install a universal cap instead of the original?
Only if it has the same specifications: 4 mm connector and 5 kΩ resistance. A cap with different or no resistance changes the ignition system's behavior and, on fuel-injected models, can create interference with the onboard electronics.