Reviews

Investigating the Top Finishing Yamaha YXZ1000R

How far from stock was it?

February 18, 2016

Jason Weller’s Yamaha YXZ1000R

How stock was the top finishing Yamaha YXZ1000R at the 2016 King of the Hammers event?UTV Driver

It’s not big news that a guy finishes 7th place in anything. However, when he does it in the world’s toughest rock racing event (King of the Hammers) in a machine that wasn’t meant for rock crawling (YXZ1000R), it raises an eyebrow or two.

Here's the performance components that were changed on Jason Weller's Yamaha YXZ1000R in order to make it a decent rock crawler. They can all be purchased through www.wellerracing.com. Call them at (480) 507-4771.

Tires:

When driving over bus sized rocks bigger is always better. Jason’s swapped out the stock 27-inch tall Maxxis Big Horns for the brand new Maxxis Liberty 8-ply tire. 30x10-14’s were used on all four corners mounted on the stock Yamaha 60th Anniversary beadlock wheels.UTV Driver

Gearing:

Not only will Weller Racing near Phoenix, Arizona be an official installer of the Tube Works gear reduction system, Weller himself proved it works. Two $2,200 systems are available; one will be a 30-percent reaction in all gears; the other is a 70-percent reduction in the ratio of first gear and 2nd through 5th will be reduced 40-percent. In addition a new oil tube is added that sprays 100 percent more oil directly on the clutch plates. Using the 70%/40% set up and the 30-inch tall tires, this YXZ still managed a 78 MPH top speed. This car also had the Rekluse Auto-Clutch upgrade.UTV Driver

Shock Springs:

PAC Racing Springs is working with Weller on a dual rate package that customers can use on their stock Fox shocks. Final spring rates have not been disclosed to us yet. This car had some internal revolving of the stock shocks as well as the Pac Springs. The springs appear to raise the car’s ground clearance as much as the taller tires do.UTV Driver

Exhaust/ ECU:

For the first time in history, an aftermarket exhaust system on a UTV makes sense. The five speed transmission will not only help the machine sound good, the low end power gains are very needed in this engine. The Weller Racing full system adds over 15 horsepower at the top (94hp total) while smoothing out power delivery across the board. If you buy the Weller exhaust for $1,399, they will re flash your ECU for $100. This changes the fuel mapping and also raises the rev limiter to 11,000 RPM.UTV Driver

Extras:

Lucky for Jason’s co pilot Kyle Anderson, the team didn’t have to use their on board Warn 4500 winch once during the entire five hour race. They did have to use a part of the spare steering assembly that you can see clamped to the front of the roll cage when they bent a tie rod. The change took them about 15 minutes. Inside the car, four spare stock axle half shafts were carried as spares but were never needed. Stock length Summer Bros Axles were outfitted on the car with the stock CV’s and boots and worked without fail.UTV Driver