Webmaster posted on September 17, 2009 21:18
YMA is pleased to announce a new locally developed variant to its comprehensive motocross lineup… the powerful and compact YZ144 two-stroke racer.
The YZ144 has been developed in Australia primarily to compete in up to 150cc two-stroke classes where it will line up alongside juniors on similar capacity machines and 250cc four-strokes in the senior Lites class.
The new machine is based around YZ125 but features increased power across the rev range and has been thoroughly tested to ensure the high level of reliability customers expect from Yamaha products.
The combination of a powerful yet reliable 144cc engine mated to six speed gearbox fitted into a lightweight YZ125 chassis is sure 
to be a serious contender not only in the Junior up to 150cc twostoke class but also MX/SX Lites and Class 1 off road competition where two-strokes up to 200cc
compete. And it is guaranteed to offer a high level of excitement to thrill seeking dirt bike riders whose main goal is fun.
The YZ144 has been developed in-house by Yamaha Racing Development (YRD) following intensive research and testing.
Press release All new YZ144 released 18 Sep 2009 Float like a butterfly, sting like a bee:
the YZ144 is set to prove that twostrokes
can be reliable, competitive
and a viable alternative to a 250F
YZ144 is fitted
with race
graphics kit
It features modifications to crankcase, cylinder and head as well as
custom made piston and ring to produce a bore and stroke of 58mm
x 54.5mm (= 143.9cc).
In order to aid and promote maintenance, each YZ144 is fitted with
an hour meter, Servicing intervals are as per YZ125 recommended
intervals. This is not a backyard bolt-on kit and due to the amount
of machining work involved, there is no plan to offer the parts as a
kit. The following modifications have been made to the standard
YZ125:
• Modified crankcase set
• Modified cylinder and cylinder head
• Modified L+R power valves
• 58mm custom made piston (made in
Germany)
• Custom made piston ring (made in
Germany)
• Hour meter
• Graphics set (front guard, rear
guard, L+R radiator shroud)
• Carburettor jets
All other specifications are as per YZ125, it even sports the
standard YZ125 exhaust system. Dyno tests in this ‘as sold’
standard trim reveal a healthy increase in power across the entire
rev range (see graph above). Owners wishing to increase power
further will have several other options available.
For example, Cisco's Race Tuning has several power up levels
available that include:
• Custom ported cylinder
• Specific 144cc exhaust
system developed by HGS
• Crankshaft modifications
(1mm off set crank pin) that
will provide a further
capacity increase to 149.2cc
(class limit is 150cc).
• VHM 144 cylinder head
• V Force reed valve
assemblies
• HPI programmable ignition
units
YZ144 is now available in limited
numbers via the Yamaha dealer
network priced $9599 RRP inc
GST.
2009 YZ144 SPECIFICATIONS
Type Liquid-cooled, 2-stroke, reed valve
Displacement - (cc) 143.9
Bore Stroke - (mm) 58.0 x 54.5
Compression 8.6 ~ 10.7:1
Lubrication Premix
Fuel Management Mikuni TMX 38
Ignition CDI
Starter Kick
Fueltank - (L) 8
Oil Capacity - (L) 0.7
Transmission 6-speed
Length - (mm) 2135
Width - (mm) 827
Height - (mm) 1315
Seat Height - (mm) 997
Wheelbase - (mm) 1443
Clearance - (mm) 386
Wet Weight 95kg with 8 litres of fuel
Suspension Front Telescopic fork
Tyres Front 80/100-21 51M
Brakes Front Single disc
Suspension Rear Swingarm
Tyres Rear 100/90-19 57M
Brakes Rear Single disc
RRP (inc GST) $9599
For more technical information, contact John Redding at YRD: (03)
9761 5871 or email: yrd@bigpond.com
For further tuning info, contact Cisco’s Race Tuning at (03 9725
1330), email: info@ciscos.com.au