This is the Novarossi BONITO.21-7XLB 7 Port Competition .21 Off Road Engine. Based on the Toro-Nero engine, Novarossi found room for improvement through a variety of subtle changes and developed the BONITO.21-7XLB. The Bonito features the redesigned 'Lighter & Lower Evo2' type cooling head that lowers the center of gravity of the engine and chassis, as well as improving cooling efficiency. Revised porting provides more linear bottom end power than the Toro with the same incredible top end delivery, while the piston design features Novarossi's 'Compact Combustion Technology', providing increased efficiency. The crank spins on a high quality ceramic rear bearing that was selected for improved performance and lifespan, while the backplate has been updated with a steel insert for reduced conrod friction and extended conrod life. 

Features: 

• Cooling Head: The 'Lighter & Lower evolution 2' type cooling head has been drilled and milled out to reduce the mass of the cooling head, reducing the Center of Gravity of the engine/car.
• Piston: The material of this piston has been chosen for its excellent strength to weight properties. The shape of the top of the piston features Novarossi's 'Compact Combustion Technology' which improves the efficiency of the engine. This piston is also milled from a single block which further increases the strength.
• Conrod: The R7 conrod is made from a super light aluminum which has been ultrasonically tested. The shape of the R7 rod reduces turbulence inside the engine while running.
• Sleeve: The sleeve has 7 transfer ports and an exhaust with booster ports. The special shape and positioning of the ports, covered by a patent, improves the internal fluid-dynamics to obtain maximum performance.
• Rear Cover: The rear cover optimizes the case volume and reduces dead space. The steel plate reduces friction and extends the lifespan of the conrod.
• Crankshaft: The crankshaft has a special shape to reduce turbulence inside the crankcase. The front part was extended to improve the seal and help to reduce fuel leaking.
• Rear Ball Bearing: The rear ball bearing has high quality ceramic balls to minimize wear and inertia to improve acceleration and fuel consumption.
• Carburetor: The carburetor is made from plastic, in "reverse" style and has a sliding throttle valve.
• Combustion Chamber: The combustion chamber is supported by an O-Ring which is placed between the combustion chamber and the crankcase to reduce the vibrations of the combustion chamber.
• Glowplug: The glowplug of engine is a Turbo type glowplug. Turbo glowplugs have a different shape than Standard glowplugs and therefor are not interchangeable able with engines that use Standard glowplugs!

Recommended Tuned Pipes: EFRA 3005, EFRA 9901, EFRA 9853 
Recommended Tuned Manifolds: 41021, 41029, 41030 

Specifications: 
Displacement: 3.49cc. 
Max. Power: 2.97 HP @ 36,300 RPM 
Practical Range: 6,000 ~ 40,700 RPM 
Bore x Stroke: 15.88mm x 17.60mm 
Transfer Ports: 7 
Ball Bearings Front: Steel 
Ball Bearings Rear: Ceramic 
Crankshaft Type: 14.5mm - Turbo SG 
Carburetor Type: 6.5mm Slide 
Carburetor Material: Plastic 
Adjustment: Single 
Glowplug Type: Turbo - C6TGC 
Exhaust Position: Rear 
Fuel Type: Advise; 25% Nitro