RZ Mark One Racing Exhaust by JIM LOMAS for Vespa PX80–200 – Right-side system for maximum peak power.
With the RZ Mark One, JIM LOMAS presents its most powerful exhaust system for the Vespa PX. The right-side exhaust system squeezes even more power out of the engines than the PERFORMANCE systems. However, this power comes on suddenly and must be handled with care.
- Right-side Racing Exhaust with a strong power peak
- Distinctive look with a right-side muffler
- Spring-loaded connections between the Exhaust Manifold, resonator, and Silencer
- Ideal for high-performance MALOSSI and POLINI setups
The silencer, which protrudes to the right beneath the engine, gives Vespa PX80–200 models an extravagant look. The spring connections between the Exhaust Manifold, resonator, and Silencer absorb even harsh compression without damaging the silencer. Installation on Sprint, Rally, and similar models is difficult and requires some modification, as the Silencer may come into contact with the Side Panels, which extend far downward.
The RZ Mark One’s impressive power peaks kick in strongly between 5,000 and 6,000 rpm. In city traffic, the resulting on-off driving sensation can be tiring. During sprints at traffic lights or on the quarter-mile, however, this very characteristic makes it all the more fun, as the Exhaust then generates plenty of thrust.
For street-tuned engines, a short 4th gear with the stock gear ratio has proven effective. If the engine has sufficient power with a well-tuned MALOSSI 210, Bell-Shaped Crankshaft, MMW Intake Manifold, and Carburettors starting at 32 mm, the RZ can also handle long gear ratios and enables high top speeds. The RZ Mark One also pairs very well with a POLINI, as it delivers plenty of power at low RPMs and, with moderate valve timing, doesn’t rev up too quickly or over-rev.
JL Warranty
For all SIP PERFORMANCE systems, first owners who purchased the Exhaust from us receive our JL Warranty. This warranty is valid for three years from the date of purchase. Should an Exhaust crack, it will be repaired or replaced by JIM LOMAS. Damage caused by curbs is excluded from this warranty.
Bolt-On Version
The bolt-on version features a flange plate for the rear silencer. This allows for the installation of common models with a 3-hole fitting as well as SIP rear silencers.
Technical Details
- Type: Racing Exhaust
- Material: Stainless steel or steel, painted black
- Silencer: Stainless steel
- Configuration: Right-hand
- Mounted to the Exhaust Manifold with Springs
- Can be installed with wide tires, a spare tire, and the Centre Stand
- Fuel mixture and ignition timing must be checked and optimized
Conclusion: Often copied but never equaled—the RZ Mark One is a high-end exhaust system tuned for peak performance on powerful Vespa PX engines.
SIP TIP:
- For 139- to 177-cc setups, a 24-mm carburettor and a longer gear ratio should be used. For 200-cc engines, a larger Main Jet is mandatory; a reinforced Clutch and a racing or Long Stroke Crankshaft are recommended. With MALOSSI or POLINI, carburettors starting at 30 mm, an MMW Intake Manifold, a tuned transmission, and SIP PERFORMANCE Ignition, you’ll have a blast while leaving others in the dust.
Feedback
“Sensational... it’s really worth the money!! Great looks and sensational performance!!!”
–SIP user “Vespa-and-more”
»Great Exhaust with top-notch workmanship, fit, and sound. (…) This thing goes like a bat out of hell!!!«
–SIP user “Tonimaroni”
Note: JL Exhausts has been struggling with a sharp rise in material and personnel costs for some time now. Customs duties, bureaucratic hurdles and a shortage of skilled workers are making production even more difficult and expensive. Unfortunately, this will lead to a price increase for all models from 07/2025. We have been able to mitigate the adjustment for the most common racing exhaust systems, but some models will be permanently removed from the range.
The exhaust systems are still manufactured by hand in Europe to the highest quality standards. Low noise development, high durability, a striking racing look thanks to clean weld seams and high-quality materials such as stainless steel continue to speak for these exhaust systems.
