Building a modern day Yamaha WR250

This is somewhat of a rehash of an older post on the subject of converting a 2006+ YZ250 to Wide-Ratio or “WR”250. The vast majority of the items needed to make this happen come straight from Yamaha. No special machining, no questionable parts, just good old Yamaha components.

I just picked up an extremely clean (like new) 2007 YZ250 and it is undergoing the primary WR upgrade. That is, an entire gear set from a WR450 is being dropped into the cases. Yes, it fits. A Boyesen Water Pump Impeller, TMV Flywheel weight (13oz), and shiny new GYTR 14 tooth countershaft sprocket. A new top end is the wise thing to do while it is down as well. That’s the meat of it right there. A wide ratio transmission in a YZ = WR. It should run over 65mph with 14-52 gearing!

Below is a photo of my other WR250 shown in that older post. It is now sporting Yamaha Blue Camo and a new IRC-VE33 for the upcoming Sandlapper Enduro in March.

2007 Yamaha WR250
2007 Yamaha WR250

That nice WR engine breathes out through an FMF Gnarly exhaust pipe coupled to an FMF Q-Stealth silencer. I pack my silencer about every 2-3 months. Quite bikes are a good thing. When did you last pack your silencer??

Of course an 18″ rear wheel is crucial and one from a WR450 will slide into place like it was made to be there. An IRC Trials Tire stuffed full of Tire Balls makes for unbelievable traction. You just can’t imagine how great a trials tire hooks up until you try one. Tire Balls in the front, some correctly valved suspension, Scotts Steering Damper, and a tall-soft seat foam smooth it all out and make it easy to ride all day long.

This particular new ride actually has a title from Ohio. It now has insurance as well. The plan is to get it licensed. A new Baja Designs LED Taillight and License Plate holder is on the way and an Acerbis Headlight is already strapped to the forks. Thinking about the Trail Tech battery for powering it all up. I just don’t trust those aftermarket stators/coils and E-Line won’t wind them for you any more.

Pictures of this “project” will be posted as progress is made. I’ll pose the same question once again . . . Why can’t Yamaha make this bike? Loyal Yamaha fans and folks that are tired of smelling the antifreeze from their overheating KTM would flock to the bikes!

One last note . . . see the header image on the top of this page. There are 3 WR250s sitting on that trail! Think about it . . .

See you on the trail!