Wet clutch
Check plate thickness, basket wear and adjustment. If the clutch slips, first identify the cause. Polini HF can be added to the kit.
MV21 buying guide · Minarelli AM6 · 2T LC
Six gears.
Your next setup.
Starting with the Rieju MRT: keep the 50 cm³ cylinder or build a 70 cm³ Sport engine. Exhaust, intake and clutch in one considered selection.
Rieju MRT · 2008–201750 → 70 cm³Manual gearbox
Build my setup ↘
MINARELLI AM6From cylinder to crankshaft.
01
Both engine and motorcycle matter
Which AM6 do you have?
The same engine does not mean identical exhaust mounts. This initial selection covers specific MRT versions with the original AM6 and a conventional carburettor. We select kits for DT, RS, RX, Beta and other AM6 models separately.
Choose the exact model and check the engine.
02
The extent of your planned build
50 to start. 70 for a fuller build.
You can keep the standard cylinder. The 70 cm³ Maxi route also includes a crankshaft and head, so plan ahead for engine disassembly and tuning.
Prices cover the selected products. Installation, tuning and extra materials are not included. We do not promise power or speed without measurements.
03
Parts that work together
Your AM6 kit.
A Race engine starts with a plan for all assemblies.
Send your motorcycle model, current cylinder, crankshaft, carburettor and goal. We can then match the exhaust, clutch, gearing and ignition.
Discuss your project with MV21 ↗Before adding to cart
This kit does not confirm the condition of your existing engine. Check the crankcases, cooling, clutch and gearbox before installation.
In this guide, the 70 cm³ conversion is intended for a closed track. For road use, check approval for the specific vehicle and exhaust; physical fitment is not a substitute.
04
Gearing, clutch and chain
AM6 needs a different drivetrain plan.
Here, power reaches the rear wheel through a clutch, six-speed gearbox and chain. Choose parts for AM6 and the specific motorcycle.
Gearbox
A larger cylinder does not repair worn gears or a worn shift mechanism. Choose gearbox and clutch oil according to the manual for your model.
Final drive ratio
The choice depends on the wheels, intended use and engine power. Taller gearing only helps if the engine can pull it.
Chain and sprocket kit
Pitch, sprocket mounts and chain length must match. The label “AM6” alone is not enough, so we do not automatically add a universal kit.
05
Ignition and spark plug
Start with the correct version.
The standard ignition does not necessarily need replacing with the cylinder. You need to know its manufacturer, connections and version-specific limitations.
Choose CDI to match the ignition
AM6 model years and electrical systems vary. Euro 4/5 electronics are not included in this initial selection. Before buying a CDI, compare the details of your existing unit and stator.
The name “sports CDI” alone does not confirm compatibility or a power increase.
Polini PVL
The manufacturer states that the original electrical system will no longer operate. This is not a simple CDI replacement for a motorcycle that needs to retain its standard lighting. Not added to the kit automatically.
…Checking availability…
View product ↗Choose the plug to match the head.
The NGK catalogue lists BR9ES for the standard MRT 50 head. For the Naraku 70 head, check the plug specification in the kit instructions. Thread diameter, reach, heat range and resistor requirements must match.
06
Before the first ride
A good setup is also well tuned.
What is included in the Naraku Maxi kit?
Cylinder and piston, matching 70 cm³ head, full-circle crankshaft, SKF C4 bearings, FKM oil seals and engine gaskets. Replacing the crankshaft requires engine disassembly. Follow the manufacturer’s tightening, tuning and running-in instructions after assembly.
Can I keep the airbox?
Yes, if the Ø34 mm connection and position suit the selected CP 19. For a sports filter, the guide selects a different carburettor connection version. In both cases, the fuel mixture needs adjusting; we do not recommend one universal jet for every setup.
Does this exhaust fit every AM6?
No. This selection uses Rieju MRT mounts. Yamaha DT, Aprilia RS/RX, Beta RR and other frames require a separate exhaust version and fitment check.
What about lubrication and cooling?
AM6 is a two-stroke engine. Check the existing oil pump, hoses, carburettor connections and cylinder manufacturer’s requirements. After engine work, bleed the cooling system and check for leaks. Do not choose the oil mixing ratio based on displacement alone.
More guides to come
Next platforms and models.
Other Derbi D50B0 versionsGeared mopedsOther AM6 motorcyclesExhaust and connections matched to the frameOther GY6 modelsFour-stroke scooters
How was this selection checked?
25 Rieju MRT versions from 2008–2017 were checked against the store’s internal fitment finder. Prices and availability are loaded from the store. Connections and existing modifications must be checked on the motorcycle.
