This is a EBMods JS Racing "TX-521R" Race Prepped .21 Nitro Engine. The JS TX-521R was designed by Ed Bridges of EB Mods with JS Racing. Ed Bridges was able to produce a high horsepower, fuel efficient, and durable engine.

The "Race Prepped" JS TX-521R is inspected by Ed before being broken in  with EBMods 30% Race Fuel prior to shipping.

Features:

• Optimized sleeve timing and port design for increased run time
• Re-enforced case for better concentric mating during thermal expansion and contraction
• Knife edged long con rod, for a broad power curve
• 14mm TiN Coated Crankshaft, for reduced friction and long life
• 2 Needle slide carburetor w/6.5, 7, and 8mm inserts included
• Cross drilled cooling head for reduced weight and increased cooling

Specifications:
Displacement: .21c.i./3.49cc
Bore: .6405"/16.26mm
Stroke: .6615"/16.8mm
Sleeve: Chrome Plated Brass
Porting Intake: 5 port + 2
Porting exhaust: Single Optimized
Crankshaft: 14mm
Carburetor: Composite Two Needle w/Adjustable Venturi 
Usable RPM Range: 40,000rpm

Recommended Pipes: Novarossi #NOV51004, manifold #NOV41021
Recommended Plugs using 30% EBMods Race Fuel:

• OS P3: High Humidity Days / Outside Ambient Temp Range 50*-70*
• OS P4: Hot and Low Humidity Days / or High Altitude Racing / Outside Ambient Temp Range 70*-100*