Yamaha reveal their all new Junior Motocross machine, the YZ65, aimed at offering a competitive stepping stone to the YZ85... It'll be arriving in Australian dealers in May with pricing TBA.
Yamaha Motor Australia has revealed an all new junior MX bike – the YZ65. The YZ65 joins Yamaha’s extensive motocross range at the entry level and offers the first step on the YZ VictorYZone ladder. The new YZ65 was unveiled to the the public at three MX tracks on the East Coast at 10am Sydney time – to coincide with the global reveal at the San Diego SX.
Yamaha’s all new for 2018 YZ65 junior motocrosser
Like all YZs, the new machine features the latest technology and performance features designed to win races and help riders become one with their machine – and placing them on top of the podium.
With a 14in front an 12in rear wheel, the new model is aimed at riders aged between seven and 12 years old. Model development is focused on being easy-to-ride so entry level racers can get up to speed quickly and progress to the next stage YZ85.
The YZ65’s 64.8cc liquid-cooled, two-stroke engine
2018 YZ65 Powerplant
The 2018 YZ65 features a new 64.8cc liquid-cooled, two-stroke engine design with a case reed-valve intake and a mechanical Yamaha Power Valve System (YPVS). Designed for performance and ease of use, the YZ65’s all-new engine also offers unparalleled durability and reliability.
Veteran engineers with over 40 years of technical knowledge — built up since the introduction of the first YZ250 in 1973 — put their know-how to work using Yamaha’s trademark YPVS system. This is the biggest contributor to the bike’s easy-to-use torque. A slit-shaped valve on the side of the exhaust port operates in response to engine rpm, moving the valve upward or downward at the top part of the exhaust port to open or close.
2018 YZ65 engine and chassis stripped down
The YZ65 uses the valve control governor proven on the YZ125 and YZ250, providing effective exhaust timing throughout the entire rev range, from low to high rpm. This delivers responsive acceleration and excellent throttle control.
The intake and exhaust systems have been designed with special attention to the pulses that occur during the combustion flow – intake, mixture, combustion, exhaust and silencing – to contribute to explosive but easy-to-usepower.
In particular, the fine-tuned shape of the air cleaner box, the shape of the reed valve – both sides were carefully examined – and an expansion chamber with plenty of volume are all prime contributors. The short exhaust complies with FIM/AMA regulations and still produces the rippling sound unique to a two-stroke.
The YZ65 powerplant includes reed valve induction and YPVS
To achieve both a high primary compression ratio and optimal inertial mass for the crankshaft, a resin weight is incorporated into the crank web. This resin balancer maintains the balance between volume and mass, giving the bike a feeling of instant power delivery while reducing the vibration felt while riding. The newly designed, lightweight connecting rod, lightweight piston and optimised crankshaft balance also help the engine dissipate vibration.
This super competitive engine is matched to a six speed transmission with ratios that optimise power output. Clutch plates and spring load have been designed for a super light clutch pull enabling enhanced machine control.
2018 Yamaha YZ65 chassis
2018 YZ65 Frame & Suspension
A newly-designed semi double-cradle steel frame, removable aluminium subframe and aluminum swing-arm provide a nimble feel and confident handling. The ergonomics feature a flat, comfortable seat and four-position adjustable aluminium tapered handlebars, to provide comfort and ease of movement for a wide range of rider builds and sizes. The chassis is designed to feel stable while riding over bumps, to have good feel and feedback from the ground, to bring consistent lap times and have stability while in the air.
Features include adjustable forks
The YZ65 adopts a race proven USD front fork from KYB with 36mm inner tubes to ensure a planted feeling when entering corners and excellent shock absorption when going over bumps. The specially machined one-piece outer tubes are made of aluminium alloy for excellent rigidity and front-end feel.
The front suspension has 215mm of travel and is adjustable for compression (12 levels) and rebound (10 levels) damping. The fork spacing is the same as the 2018 model YZ85 at 175mm. Combined with the lightweight aluminium steering stem, this front suspension offers supreme handling with a light and stable feel but also a solid connection to the ground.
A single rear shock is also adjustable with a rigid swingarm
The rear combines a newly designed Monocross suspension with an aluminum swingarm. The rear suspension has a smooth damping feel designed not to bottom out and helps deliver the machine’s stable and planted sensation when absorbing shocks. There are 10 levels of adjustment for compression and rebound damping.
2018 Yamaha YZ65
The swingarm’s rigidity balance is tuned for the frame and helps give the bike its light handling feel and easy lean-in characteristics. Its high rigidity and balance with the frame are major contributors to the bike’s excellent off-road performance. Also, the swingarm end’s shape was designed for easy maintenance. The resin chain guard is not only light, but is also designed to be compact enough not to get caught up in ruts that the small-sized wheel will travel through.
2018 Yamaha YZ65
2018 YZ65 Styling & Ergonomics
The handlebar crown is made of strong, lightweight cast aluminium while the tapered handlebars are also aluminium. The handlebar position can be adjusted for four levels from front to back in order to match a child’s growth by changing the bar clamp’s orientation and mounting location. The maximum range of adjustability is 27 mm (Forward: 10 mm / Backward:7 mm or a further 10 mm for 17 mm).
The newly designed seat’s shape and fit makes it easy for the rider to shift their weight forward and backward. With an eye on easier maintenance, just a single bolt on top is required to remove it. In addition, for ease of use, the bolt is located under the seat cushioning.
2018 Yamaha YZ65
Other cool featrures include YZ450F inspired graphics that are integral with the body panels for a shared YZ family look. This is underlined by the same coloured blue rims front and rear and gold-coloured chain.
“We have had ongoing communication throughout testing and development of the YZ65 and believe it will more than competitive with anything currently available in the class. Test riders in the US are extremely confident of the bike’s performance and reliability as it has exceeded Yamaha’s industry leading standards in performance, handling and durability,” says YMA Junior Race Team Manager Scott Bishop. “We look forward to adding this bike to our arsenal of YZ weapons in 2018 and starting our YJR development program with riders at an even younger age. We are excited to campaign the YZ65 and believe it will be an immediate success on and off the track.”
2018 Yamaha YZ65 Specifications
Engine type: 65cc liquid-cooled 2-stroke; reed-valve inducted
Bore x stroke: 43.5mm x 43.6mm
Compression ratio: 8.1~9.6:1
Fuel delivery: Keihin carburettor
Transmission: 6-speed; multiplate wet clutch
Final drive: Chain Suspension
Front: 36mm KYB telescopic fork, adjustable compression and rebound damping; 215mm travel Suspension
Rear: Single shock, adjustable compression and rebound damping; 269mm travel
Brakes: 198mm hydraulic disc front, 190mm hydraulic disc rear
Tyres: Maxxis Maxxcross SI Tyres, 60/100-14, 80/100-12
L x W x H: 1613mm x 762mm 1003mm
Seat height: 749mm
Wheelbase: 1143mm
Rake (caster angle): 26.4°
Trail: 63.5mm
Max ground clearance: 267mm
Fuel capacity: 3.4 litre
Wet weight (with all fluids and full fuel tank): 60.8kg
Warranty: 30 Day (Limited Factory Warranty)
Availability: May 2018
RRP (inc GST): TBA
2018 Yamaha YZ65
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