YAMAHA YZ250F PROJECT: BEHIND THE BUILD

The 2021 Yamaha YZ250F won our 2021 250 MX Shootout. It’s a great bike with excellent suspension and a good-solid power delivery. There’s only one problem. All the bikes in our 2021 250 MX shootout were great bikes with glowing attributes. In the 50-year-history of Dirt Bike Magazine, we never came out of a shootout with such indecision over which bike was best. We decided to do something about it. The winner was turned over to Simi Valley Cycle with somewhat nebulous instructions: make it better. Here’s what resulted, point by point.

Precision Concepts re-valved and re-sprung both ends of the SVC YZ250F for our motocross application.
The MotoSeat semi-custom seat covers are constructed of a rubberized material for traction in all conditions and is UV-protected and double-stitched for durability.
ODI’s Ricky Carmichael-edition RC4-bend Podium Flight handlebars are constructed of a 2014-T6 for increased strength, with ODI’s exclusive tubing profile and design for a non-braced handlebar.
IMS core pegs are available in three different platform sizes, along with a standard and aggressive tooth design. Each Core peg is constructed from heat-treated 17-4 stainless steel.
Xtrig ROCS Pro triple clamps are machined from billet aluminum and feature multiple offset options. The handlebars can be mounted in 12 different positions with the Progressive Handlebar Dampening System (PHDS) handlebar mounts.

Kevin at ZLT designed a semi-custom set of graphics that gave the SVC Yamaha YZ250F a clean factory look that incorporated our MotoSeat gripper seat cover into the overall design.
Moto Hose silicone radiator hose kits are available in a variety of colors and are constructed of a higher-grade rubber than the OEM units and infused with silicone.
The new Works billet clutch cover from Boyesen is CNC-machined and hard-coated to resist scratching. The
Hoosier IMX20 tires feature a spaced-out tread pattern and proprietary rubber compound designed specifically for motocross and Supercross applications.

The T6 complete exhaust system features stainless steel tubing and an aluminum muffler and is designed to provide performance gain across the entire power curve. Each system is equipped with a removable USDA-approved spark arrestor.

Twin Air’s PowerFlow kits are designed to ensure a leak-proof, fool-proof fit with a rigid, lightweight, billet-aluminum cage and a billet-aluminum flange with a rubber seal that bolts tightly to your airbox. Dual-stage air filters are also included in each kit.

FCP Racing engine mounts are designed to improve overall handling, and feature CNC-machined top mounts and titanium front mounts. It’s used under the radar by many factory-level Supercross and motocross professional teams.

In the end, we had a more decisive winner. It still wasn’t the fastest of all the 250 motocross bikes, but it was a sweet and easy to ride. If the bike had come this way, it would have been an easy winner. The problem, of course, remains that you could do most of these modifications to any of the 250s and that puts you back to square one, in the middle of a pack of outrageously good bikes. The rest is up to you.