JUSTIN HOEFT’S YAMAHA YZ85: TWO-STROKE TUESDAY

We are throwing things back to 2012 on this week’s Two-Stroke Tuesday. The Yamaha YZ85 featured this week was part of a story called “Three Amigos” where we built a YZ85, YZ125 and YZ250. This YZ85 was raced by Justin Hoeft who at the time was in the supermini class and received some support from Yamaha. As always we packed 2-Stroke Theater with premix burning machines for your viewing enjoyment. Don’t miss the exclusive link to an insane Kawasaki KX65 build at the bottom of this post!

The chassis got major updates. GYTR offers a complete Super Mini chassis kit that includes longer front and rear brake lines, a longer rear swingarm, bushings, bearings, collars, oil seals and plugs. We topped it off with front and rear GYTR wheels through Dubya USA utilizing Talon hubs, spline-drive heavy-duty spokes and Excel rims.

Since its introduction in 2002, the Yamaha YZ85 has remained relatively unchanged—except for small parts and minor styling changes. Ten years later, the bike is almost identical. Justin Hoeft was a top amateur racer back in 2012 with limited support from Yamaha through Thousand Oaks Powersport and also a Dirt Bike test consultant.

This machine was a ripper!

The engine received a complete GYTR 112cc big-bore kit made by Athena. This complete kit includes a new precision-made, stroked crankshaft and nickel-carbide-plated cylinder with enlarged water passages and revised porting designed specifically for improved performance. The cylinder head is also designed with enlarged water passages. The GYTR kit has everything needed for a complete installation—except the required crankcase machining. It includes a crankshaft, connecting rod, cylinder, cylinder head, precision-made piston with rings, clips, wrist pin, studs, nuts, O-rings, and gaskets (different-thickness base gaskets to adjust squish).To help the bike breathe, we installed a GYTR complete exhaust by FMF, a V-force reed valve, and a dual-stage, high-flow air filter. A GYTR complete clutch was also installed, which included a billet clutch basket, billet clutch pressure plate, billet inner clutch hub and a stock Yamaha clutch kit.

With the major updates completed, Hoeft bolted on a GYTR chain and sprocket kit and Tag bars, and Factory Connection handled all the hard work in the suspension department.