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 cap that connects the high-voltage cable to the spark plug. "Shielded" means it incorporates a 5 kΩ resistor: this suppresses electromagnetic interference generated by the spark, which would otherwise confuse the ECU, immobilizer, and digital instrumentation. On a modern scooter, this is not a minor detail: a cap with an out-of-spec resistor or an oxidized contact can cause difficult starting, unstable idle, acceleration gaps, and, in the worst cases, warning lights and erratic readings on the dashboard. It is the manufacturer-specified replacement part for a huge portion of Piaggio Group's production: Beverly, X9, X Evo, MP3, Carnaby, Nexus, Runner 4T, Atlantic, Sport City, Scarabeo, and Vespa ET4.

✓ Strengths

• Original Piaggio spare part — part number 293845, official name "CAPPUCCIO SCHERMATO" (SHIELDED CAP)
• Integrated 5 kΩ resistor — interference suppression, as required by electronic control units
• Ø 4 mm connection, the standard size for Piaggio Group high-voltage cables
• Extensive coverage — a single part number for Piaggio, Aprilia, Gilera, Vespa, and Scarabeo, from 125cc to 500cc
• New contact — eliminates oxidation that causes spark loss without obvious symptoms
• Immediate installation — screws onto the existing cable, no special tools required

Technical Features

Vehicle Compatibility

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

Recommended products

The cap works together with the high-voltage cable and the spark plug: if you are chasing an ignition problem, replacing them together is inexpensive and resolves the issue in a single intervention. In our catalog, you will find the original Piaggio HV cable and the spark plugs specified for your model, as well as the high-voltage coil if the fault is further upstream.

Perfect for

• Those experiencing difficult starting or unstable idle and have already checked the spark plug and battery
• Workshops and service centers that work on Piaggio Group maxi-scooters and want to keep the most commonly used cap in stock
• Those performing preventive maintenance and replacing the cap along with the spark plug and cable during major services
• Those with digital instrumentation showing strange readings when the engine is running: an unshielded or degraded cap is a classic cause

Frequently Asked Questions

What is the Piaggio 293845 shielded spark plug cap?
It is the original cap that connects 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, in this case 5 kΩ, which attenuates radio interference generated by the discharge. This serves to protect the ECU, immobilizer, and digital instrumentation: on injected vehicles, a cap without a resistor can cause electronic malfunctions.

How do I know if the cap needs to be replaced?
Typical symptoms include difficult cold starting, unstable idle, acceleration gaps, and increased fuel consumption. When removed, you often see green oxidation on the internal contact, cracks in the rubber, or black discharge marks on the outer 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 characteristics: a 4 mm connection and a 5 kΩ resistor. A cap with a different resistance or no resistance will change the behavior of the ignition system and, on injected models, can cause disturbances to the onboard electronics.