Naraku
Naraku 70cc Cylinder Kit - Yamaha Jog/Zuma AC Minarelli
Description
This Naraku 70cc Big Bore Cylinder Kit (SKU 137-26) takes an air-cooled horizontal Minarelli 2-stroke, the engine used in the Yamaha Jog and Zuma and in many other 50cc scooters, up to 70cc with the stock crankshaft. It is a complete bore-up kit with a 47mm cylinder, a low-friction molybdenum-coated flat-top piston, rings, a 10mm wrist pin, circlips, and head, base, and exhaust gaskets.
Key Features
- 70cc displacement: 47mm bore raises a 50cc engine to 70cc with the stock crank.
- Moly-coated piston: Low-friction flat-top piston reduces wear.
- Complete kit: Includes cylinder, piston, rings, wrist pin, circlips, and a full gasket set.
- Exhaust flexibility: Works with a stock or performance exhaust.
- Head options: Runs with the stock head for higher compression or with a larger 70cc head.
Kit Contents
- Cylinder, 47mm bore
- Molybdenum-coated flat-top piston with Naraku logo
- Piston rings
- 10mm wrist pin (wrist pin bearing not included)
- Circlips (x2)
- Head gasket
- Base gasket
- Exhaust gasket
Technical Specifications
- Part number: 137-26
- Displacement: 70cc with stock crankshaft
- Cylinder bore: 47mm
- Cylinder sleeve outer diameter: 50.5mm
- Wrist pin diameter: 10mm
- Wrist pin bearing: Not included
- Cooling: Air-cooled only
- Engine type: Air-cooled horizontal Minarelli 2-stroke
- Brand: Naraku (aftermarket)
Compatibility
This kit fits air-cooled horizontal Minarelli 2-stroke engines that use a 10mm wrist pin.
| Make | Fits | Does Not Fit |
|---|---|---|
| Yamaha Zuma | Zuma 50 (2002-2011), horizontal AC Minarelli, engine code 5YW / CW50 | Zuma 1989-2001 (vertical Minarelli) or Zuma 50F / 50FX 2012+ (4-stroke) |
| Yamaha Jog and Vino | Jog 50 (1992-2001), Vino 50 2-stroke | Aerox and other liquid-cooled models |
| Genuine | Buddy 50, RoughHouse 50 (horizontal Minarelli-type engine, 10mm wrist pin) | |
| Aprilia | Scarabeo 50 (1993-2006), SR50 air-cooled (1994-2002) | SR50 LC (liquid-cooled) |
| CPI | Oliver 50, Hussar 50, Popcorn 50 | |
| E-Ton | Beamer 2 | |
| Malaguti | Ciak 50 (2002-2005), F10, F12 AC, F15 AC, Yesterday 50 (2001-2006) | Liquid-cooled versions |
| Benelli | Pepe 50, Andretti 50 | |
| Adly | Thunder Bike 50 | |
| MuZ / MZ-Moskito | RX50, SX50 | |
| Chinese 2-stroke clones | 1E40QMB / 1PE40QMB engines with a 10mm wrist pin | Clone engines with a 12mm wrist pin |
Check the engine on your scooter before ordering. Confirm it is air-cooled and horizontally mounted, and measure the wrist pin. Some 1E40QMB / 1PE40QMB Chinese clone engines use a 12mm wrist pin instead of 10mm, and this kit will not fit those.
Installation Notes
- Cylinder sleeve clearance: The sleeve outer diameter is 50.5mm. Some engine cases need light filing or machining at the case mouth so the skirt slides in smoothly.
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Carburetor and jetting: Going from 50cc to 70cc requires upjetting the main jet, typically 10% to 15% larger, to avoid running lean and seizing the piston.
This product is intended for off-road use only. This product is not intended for use on public roads or land.
Product Diagrams
Features
Specifications
Part Number: 137-26 | Displacement: 70cc (stock crank) | Bore: 47mm | Sleeve OD: 50.5mm | Wrist Pin: 10mm | Wrist Pin Bearing: Not included | Cooling: Air-cooled only | Engine: AC horizontal Minarelli 2T | Includes: Cylinder, piston, rings, pin, circlips, head/base/exhaust gaskets | Brand: Naraku
Model Fitments
Air-cooled horizontal Minarelli 2-stroke, 10mm wrist pin: Yamaha Zuma 50 2002-2011 (5YW/CW50), Jog 50 1992-2001, Vino 2T; Genuine Buddy 50, RoughHouse 50; Aprilia Scarabeo 50, SR50 AC; CPI Oliver/Hussar/Popcorn; E-Ton Beamer 2; Malaguti, Benelli, Adly, MuZ AC models. Not pre-2002 Zuma, 2012+ Zuma 4T, LC models, or 12mm-pin clones.
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Same day shipping for orders placed before 2PM (CST) M-F
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30-day return period on eligible items
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Flat-rate shipping for orders shipped to the 48 Contiguous United States.
