New Low Profile Head by HASI TUNED, this head in addition to lowering the centre of gravity, due to a saving of 3.8 grams compared to the original.

These heads has been specially produced for engines with AAC liner, as it guarantees a faster and easier warm-up of the engine.

Affordable Liner/Sleeve Remover tool for all OS based .21 nitro engines.

Enlarged fuel window.
Enjoy a wider and more precise tuning range, making carburation faster, easier, and more stable under all conditions.

More control.
Less guesswork.
High-grade stainless steel construction Precision-machined for optimal fuel atomisation inside the carburetor, ensuring better efficiency and improved throttle response at high RPM.

Full compatibility Direct fit for all OS 21M2 series carburettors.

📦 Now available as an optional upgrade for all OS-based engines.

THESE WORK!!!

MAIN JET SEALS.

8mm, 8.5mm and 9mm

Hasi Tuned High Performance Venturi 9.00 mm Ultra Short Version

Fits all OS based carburettors.

Similar design to MAX engine short venturi. Immediate power increase.

Hasi Tuned 9 PORT AAC 2026

Hasi Tuned 7 PORT AAC 2026

CLEAR INS BOX EFRA APPROVED

BLACK INS BOX EFRA APPROVED

PACK OF 6.

SALE SPECIAL - 1 ONLY

• - New high dissipation and low density aluminium cooling head, to  combine functionality and lightweight.
• - New crankshaft, with revised timing and balancing.
• - New piston and liner, 7 PORTS with high compression piston made from rod.
• - New reinforced 'GENUINE OS' conrod.
• - New type Low Profile head - RED.

Each engine will have its own dedicated sleeve, which will be perfectly honed inside the crankcase, avoiding dangerous vibrations; the design of the ports has been revised to combine performance and reliability.

COMES COMPLETE WITH 'PRE-RUN' (Proper running not oil bath!) + Hasi Special Back Plate

Like every Hasi engine, they are numbered one by one and accompanied by a certificate of guarantee and authenticity and the useful engine book.

Hasi Tuned High Quality After Run Oil 50 ml.

HIPEX SHORT EXHAUST SPRINGS  x6 (1/10th and 1/8th)

IN STOCK NOW.     ** WORLD CHAMPIONS 2019 ** 

Available as Motor only or with OS Pipe & New 'O2' Manifold, Springs and Gaskets. See Drop-Down box.

This New 9-port power plant was developed with this year's IFMAR 1/8th Nitro On-Road World Championship* in mind. It features an updated piston and liner design that increases overall torque, while the DLC coated crankshaft offers improve transition from low to high rpms. The engine also sports a new combustion camber insert with a silicone O-ring, adapted from O.S. Engine’s off-road engines, preventing dust and dirt contamination. The R2104 is rounded off with a new design cooling head in a 2-tone black and red finish with white laser-engraved graphics.

• The cylinder liner uses a new 9 port design
• The cylinder head uses a two-colour anodising 
• Increased fin pitch achieves both cooling performance and weight
  balance
• Equipped with 21M2 (B) slide carburettor.

Specification

Available as Motor only or with OS Pipe & New 'O2' Manifold, Springs and Gaskets (saving over £80) 
See Drop-Down box.

This special Speed version of the OS RP7 glowplug is plated in 24K gold. But the gold is not just for added for cosmetic 'bling' as the gold plating was chosen for its thermal characteristics in order to improve throttle response in medium and low speed ranges over a standard plug.

ONE LEFT WITH MAXIMA MODIFIED BACK-PLATE

Maxima MX Europa have introduced their new .21 engine for 1/8 On-Road class, the Maxima Mx R6.

Over the past years several tests have been done with Mx R2 and Mx R4 to get to the R6,
with all the quality standard of our engines and overall performance regarding torque and runtime.

The Mx R6 is based on O.S Speed R2103 with special factory modifications to Crankshaft, Liner and
Piston and comes 'Pre-Run' to shorten the running in process by half!

Main Features: 
Lower Centre of gravity for better handling
• A second inner button head allows for finer tuning to meet track conditions
• New ceramic rear bearing reduces friction loss 
• Compatible with 16% nitro fuel, which complies with EFRA regulations
• Retains O.S Speed innovations such as DLC coating and tungsten weighted crank shaft

Power with Economy! 

All motors are factory selected, tuned and modified by Maxima.

PLEASE NOTE:
ALL MAXIMA MOTORS ARE SUPPLIED PRE-RUN USING OIL BATH METHOD (Not fully run-in)

INS-BOX Air Filter and Intake Silencer. 

Suits all .21 On-Road motors.

MAX POWER CONICAL MANIFOLD 90+90 DEGREE (1+1) 02299

PRICE INCLUDES:

HARD COATING

The latest and greatest pipe and manifold kit from 'the master'. 

Designed specifically for the MAXPOWER .21 motors but...... 

Tests have proved them to work supremely well on HASI/OS based & NOVA motors.

HARD COATED.

Dust Rubber Protector & Ring for Max Power & Novarossi

MAX SLEEVE REMOVAL TOOL (.21)

MX-21 351 9 Port 14.5mm Crankshaft.

Ceramic Bearing Rear 14.5mm

California Head.

ABC Piston & Liner.

NOTE: Extras included in this price:

• DLC COATED CRANKSHAFT

• BLACK Coated Crankcase

In stock Now.

PISTON WRIST PIN (Special Tin Coated)

STRONG +1mm CONROD .12

CONROD .21 V.Fuel Strong

REAR 'STEEL' BEARINGS

FOR 14mm CRANK ONLY

REAR 'CERAMIC' BEARINGS

FOR 14mm CRANK ONLY

'CERAMIC' REAR BEARING SPECIAL  11 BALL

FOR 14.5MM CRANK ONLY

THE 2025 WORLD CHAMPIONSHIP WINNING MOTOR IN 

TAKAHATA SHOKI'S MUGEN MRX7.

ALSO USED BY DARIO BALESTRI TO WIN THE 2025 EUROS

• MX-21 351R 9 Port 14.5mm Crankshaft.
• Ceramic Bearing Rear
• QUADRIFOGLIO head.
  
• AAC Piston & Liner
• DLC Coated Crankshaft.

  
  
  

  In stock Now.

IN STOCK 'NOW'

COLLECT FROM STORE OR AT MOST NATIONAL MEETINGS BY ARRANGEMENT

Made for MAXIMA by the world famous PEPE GROUP to the same specification as the highly respected ENERGY fuel.

4 litre tins.

OS Quality in an Affordable package.

High Performance for a budget price.

Featuring improved torque at medium to low speeds, the throttle response has also been improved.

This has been achieved through a newly designed crankshaft with different counter weight shape which has had two tungsten weights installed for improve performance.

The cooling head has also been changed to improve cooling, while the button and its o-ring has been modified to prevent dust entering this area.

• New inner crankshaft.
• New Cooling-head increased cooling.
• New combustion chamber/o-ring.

New Pipe & Manifold: 1070SC(EFRA2672)/MT03

IN STOCK NOW.

The BRAND NEW EUROSPEC II Motor from OS Engines.

(Price does NOT INCLUDE Pipe & Manifold.)

• NEW CRANKSHAFT. Featuring an extra Tungsten counter balance weigh to improve mid range performance and 'return to idle' function. 
• NEW LINER & PISTON. 7 ports (similar to Shimo II) for a smoother power delivery with increased torque. Exhaust side extra liner ports to improve piston cooling and a better heat distribution.
• New Head Graphics.

We proudly present the O.S. SPEED R21 Shimo3 Edition, developed in collaboration with Takaaki Shimo, multiple podium finisher at the IFMAR 1/8 Racing World Championship.

This 9-port engine features a specially treated piston and a newly matched cylinder for enhanced durability and longer lifespan.

The LGC cooling head and 8.5mm carburettor restrictor are anodised in a distinctive colour exclusive to this edition.

Additional upgrades include a new Dust Cover Ring and Exhaust Spacers to fine-tune engine performance to your preference.

This package comes complete with the latest EFRA2196 tuned muffler and its MR05 manifold, making it a truly special edition for performance enthusiasts.

Genuine OS parts.

Suitable for  ALL OS .21 motors.

Genuine OS parts. Suits all OS .12 motors from 1201 to 1204

OS12 WRIST PIN.

Genuine OS parts.
CERAMIC REAR BEARING
Suits all OS .12 motors from 1201 to 1204

OS Exhaust gasket 21 BLACK (2)

OS23730020

23730050

 R2101/2/3/4/5 & MAXIMA R6

With 3 Piston Circlips

• VSR01
• VSR02
• VSPTO01
• VSM01
• OS R2101
• OS R2102
• OS R2103
• OS R21 EURO
• OS 21XZ-R
  OS 21XZ-GT

Length: .53" (13.5mm)
Diameter: .16" (4mm)

'O' Rings for Mixture Control Valve (x2)

OS 21 CARBURETTOR COMPLETE

ALL OS 1/8th ON ROAD MOTORS

NOT 2105