This is the Ultimate M5S based on the OS B2103 Type R competition engine & Ultimate 2141 pipe combo.

The 5-port long-stroke engine offers great power at medium-high speeds. The cooling head, the crankcase cover plate and the carburetor feature a new design. The new DLC-coated crankshaft has two tungsten counterweights for smooth rotation and better balancing. It comes with ceramic rear bearing, the 22E carburetor and an O-ring under the cooling head for reducing vibration and preventing dust from entering the engine.

This engine has been developed for medium to high speed tracks.

This combo comes with the EFRA 2141 pipe. This EFRA 2141 hi-quality aluminum exhaust has been designed to improve the overall performance of your engine. It produces a precise and linear throttle response in the low to mid RPM range with a great top end speed. This pipe set will provide great power to your engine up to the high RPM range to produce a great and easy to drive power curve.

All these characteristics will provide great torque for those very demanding tracks with sharp corners and hard to clear jumps.

The EFRA 2141 exhaust system is a great choice for your 1:8 off road engine, and it’s specially recommended for the M3R, M3X, M4R and M5 Ultimate engines

This exhaust system includes the pipe, the manifold, 3 short springs, 2 medium springs, 1 long spring and 2 manifold gaskets.

Features:

• The long-stroke off-road engine put a high value on beasty power in mid-high speed range.
• The cooling head, carburetor, crankcase cover plate are designed new.
• The new DLC-coated crankshaft has two tungsten counterweights for smooth rotation and better balancing.
• Ceramic rear bearing.
• O-ring under the cooling head for reducing vibration and preventing dust from entering the engine.
• A newly designed 22E carburetor for producing high power
• EFRA 2141 exhaust system

Technical specifications:

• displacement 3.49cc
• bore 16.27mm
• stroke 16.80mm
• rpm 4000-42000 rpm
• max output 2.64hp/34000 rpm
• weight 352gr
• exhaust: UR352141
• port 5-port