Products 21 Sep 2009

Yamaha releases YZ144 motocrosser

Yamaha Australia has revealed details on a locally developed variant to its comprehensive motocross line-up, a YZ144 two-stroke.


Yamaha's locally developed YZ144 in action

Yamaha's locally developed YZ144 in action

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.

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 in standard trim reveal a healthy increase in power across the entire rev range. 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.