Piaggio 487042 Champion RL82C Spark Plug Short Thread – Vespa PX 125-150 (1998-2017)

The original Piaggio spark plug 487042 is the Champion RL82C, the original equipment spark plug for the Vespa PX 125 and PX 150. It is a short-reach resistor spark plug: Ø 14 mm thread, 12.7 mm long, 20.8 mm hex, flat seat with gasket. It comes new in the original Piaggio Group packaging. Product code 487042.

✓ Strengths

• It is the spark plug specified in the catalog – code 487042 is the one assigned by the official Piaggio spare parts catalog to the PX 125 and PX 150, with no conversion tables to interpret.
• Short reach, the detail that matters – 12.7 mm thread: mistakenly installing a long-reach spark plug on this cylinder head risks hitting the piston.
• Resistor – the R in the designation indicates the integrated interference suppression resistor, which protects the control unit, tachometer, and electrical system from electromagnetic interference.
• Copper core – dissipates heat well and brings the spark plug to temperature quickly, typical of scooter stop-and-go city driving.
• Original Piaggio Group packaging – new and never-before-installed spare part, in Genuine Spare Parts box.

✓ Technical specifications

✓ Vehicle compatibility

The list is taken from the official Piaggio spare parts catalog (B2B area). If in doubt, send us your scooter's chassis number and we will verify the correct code for you.

✓ Who is it perfect for

For those who own a Vespa PX and actually use it: the spark plug is the most frequently replaced spare part and the easiest to get wrong, because alternatives with long threads or without resistors are often offered at the counter. If you are doing a service, if the PX starts with difficulty in the cold, or if the engine has lost its liveliness uphill, this is the spark plug the manufacturer intended for that engine. It is also the right part to keep under the seat as a spare: it costs only a few euros, weighs nothing, and saves you from being stranded far from home.

Frequently Asked Questions

Which Vespas use the 487042 spark plug?
It is fitted on the Vespa PX 125 E and PX 150 E from the historical catalogs 1998-2005, on the PX 125 and PX 150 two-stroke produced from 2011 to 2017, and on the special series PX 125 30 Anni four-stroke from 2007-2008. The list is from the official Piaggio spare parts catalog.

What does "short reach" mean and why is it important?
The reach is the length of the threaded part that enters the cylinder head: here it is 12.7 mm, compared to 19 mm for long-reach spark plugs. The diameter is the same, Ø 14 mm, so an incorrect spark plug will screw in but protrude into the combustion chamber and can touch the piston.

What does the code RL82C mean?
It is the Champion spark plug code, printed in black on the white insulator. The initial R indicates that the spark plug is resistive, meaning shielded against electromagnetic interference. The corresponding original Piaggio code is 487042, which you will find printed on the box.

What electrode gap should it be installed with?
The Champion RL82C is supplied with an electrode gap of 0.6 mm. This is the value to check with a feeler gauge before installation, because the ground electrode can shift in storage or during transport. If in doubt, refer to the value indicated in your scooter's owner's manual.

Can I install an equivalent NGK?
Conversion tables indicate the NGK BR7HS as an equivalent to the Champion RL82C. However, this remains an indicative equivalent: the spark plug specified by the manufacturer for these engines is 487042, and for a spare part that costs only a few euros, it is advisable to stick with the original.

How many are needed and what wrench do I use to change it?
Only one, because all engines in the table are single-cylinder: the indicated price refers to a single piece. To remove it, you need a 21 mm spark plug wrench, which corresponds to the 20.8 mm hex of the spark plug. Always work with a cold engine.

How often should the PX spark plug be changed?
Follow the maintenance plan in your scooter's owner's manual. In practice, it's a good idea to remove it at each service and examine it: the color of the insulator and the condition of the electrode immediately tell you how the carburetion is working, which changes with the season and altitude on a two-stroke engine.