Ultimate MXZ Nitro Engine Set with 2142 Pipe #UR3401-MXZC3X

Description

The Ultimate MXZ .21 “Team Edition” engine combo delivers premium power, efficiency, and reliability for 1/8 off-road competition. Manufactured by the world-renowned O.S. Engines in Japan, this long-stroke powerhouse includes the Airmax dual-stage air filter and the Ultimate 2142 Superstrong one-piece exhaust system for unmatched performance on any terrain.

Cooling Head

The MXZ features an 8-fin low-profile cooling head designed for maximum airflow to the glow plug. This results in improved temperature stability, smoother carburetion, and reliable idle—especially under racing conditions.

Carburetor – OS 21 J3 Custom-Modified

Equipped with the 21 J3 carburetor, this engine benefits from a redesigned high-speed needle holder that enhances fuel cooling and improves idle consistency, throttle response, and fuel mileage.
A new dual-stopper uniball joint allows easy adjustment of the carb linkage angle without disassembling the engine—an ideal upgrade for pro-level tuners.

Crankshaft & Bearings

A 14 mm crankshaft with a teardrop-shaped intake and paste insert improves mixture flow, while the engine is fitted with:

OS steel rear bearing

Ultimate Racing double-sealed front bearing
Together they deliver long-lasting precision and reduced friction.

FLOWMAX 6.5 mm Venturi

This innovative FLOWMAX venturi features a longer and wider base than standard designs, perfectly aligning with the carb bore for smoother airflow. The result? More power from smaller venturis—and improved fuel efficiency.

Sleeve & Piston

The 3+1 port sleeve delivers strong but linear power with excellent throttle feel. Both the sleeve and piston are machined from high-strength aluminum bar stock for outstanding durability.

Technical Specifications:

• Displacement: 3.49 cc
• Bore x Stroke: 16.27 x 16.80 mm (Long Stroke)
• Sleeve: 3 inlet ports + 1 exhaust
• RPM Range: 4,000 – 40,500
• Max Output: 2.55 HP @ 34,000 RPM
• Weight: 350 g
• Crankshaft: 14 mm
• Carburetor: 21 J3
• Glow Plug: P3 Turbo
• Exhaust Position: Rear

Includes:

• Ultimate MXZ .21 Engine (Team Edition)
• Ultimate Airmax High-Flow Air Filter
• Ultimate 2142 Superstrong One-Piece Pipe Set

Why choose the MXZ “Team Edition”?

• Engineered by O.S. Japan for maximum durability and precision
• Race-proven cooling and fuel efficiency upgrades
• Enhanced throttle response and tuning flexibility
• Complete performance package – ready to dominate the track