On this week’s Two-Stroke Tuesday we take a look back at a Yamaha YZ144 big-bore project we did in 2012. We gave the machine more horsepower and some updated styling. There are products from Kenda and Torc 1 Racing featured in 2-Stroke Hardware and it’s all about 125cc machines in 2-Stroke Theater. If you’re a fan of the YZ125 or other small bore two-strokes check out the exclusive link to our 125 Stroker project at the bottom of this post.

We installed an Athena 144 big-bore kit that included a brand-new nickel-carbide-plated cylinder (with enlarged water passages), cylinder head, 58mm Vertex piston with rings, pins, clips, gaskets, modified power valves, O-rings and complete instructions. Best of all, it fits all 2005–’12 Yamaha YZ125 models. The kit was a little more involved to install than we initially thought. After actually reading the instructions first for once, we discovered the need to grind some clearance from the cases for the oversized piston. (Just an FYI) For this you need to split the cases.

A Pro Circuit factory-finished pipe and 304 shorty silencer helped our YZ144 with those extra ponies on the mid- to top-end pull. We installed a complete Hinson billet clutch that included a clutch basket with a kickstarter gear, an inner hub, a pressure plate, fiber plates, steel plates and springs.

The major change that is visible to the eye was the installation of a white UFO Yamaha two-stroke restyle kit. UFO’s restyle kit bolts right up to all the existing mounting spots, so no drilling or cutting is involved. The kit gave our YZ125 a look similar to the YZ250F. The front fender, front number plate and rear fenders are almost identical. The radiator shrouds and side number plates have a YZ250F styling hint without going overboard. Dirt Digits Graphics made the kit flow, and the white SDG seat took the style factor to an entirely different level.

The ARC adjustable clutch perch and ODI super-soft grips are a great combination of comfort and function.

Enzo Racing probably has the most testing time with the KYB components that are stock on the YZ125. Ross Maeda, Wil Decker and Craig Decker have countless hours logged supporting all the factory and privateer race teams of the era when two-strokes reigned supreme. So, it seemed like an easy decision to have them work over the suspension.

Applied Racing’s R/S triple clamp set gave us the option of running rubber- or solid-mounted bars with loads of adjustability.

We used Warp 9’s complete wheel sets with blue hubs, black spokes and black rims. The rear wheel comes equipped with a brake rotor and sprocket, while the front includes the brake rotor. We also installed Ride Engineering’s steel-braded brake lines to give us that extra stopping power.



The new Kenda IBEX tires are designed for low speed, technical enduro trail type riding for traction in all kinds of weather conditions. They feature a super-soft almost gummy rubber compound, an open aggressive tread pattern, flexible carcass and a shoulder knob designed for a large contact patch for maximum traction.
Contact: www.kendatire.com 


With a billet aluminum construction, anodized finish, breakaway slim flex design and a stainless steel pivot point mechanism the Vengeance levers from Torc 1 Racing is built to improve performance and durability. Each kit contains an extra black lever.
Contact: www.torc1racing.com


If you like the Yamaha YZ125 featured on this week’s Two-Stroke Tuesday check out this sweet YZ125 Stroker project we did with C4MX. Click the image below for more information.


Comments are closed.