The YZ250 Yamaha Should be Selling: 3DP-YZ Build
As we all know, the Yamaha YZ-250 has remained essentially unchanged since 2006, almost 20 years ago at this point. Yes, we’re aware that plastics have been changed over the years, but the nuts and bolts of the bike are still straight out of 2006 and it shows. It’s still a solid platform, but having owned one since 2015 we had to wonder what the bike could be if Yamaha gave it some real attention. Over the last few years we’ve slowly been making changes, swapping parts, and creating what we think is the ultimate YZ-250 based on available parts and mods. In this post we’ll go over the major changes we made, why we made them, and what effect they’ve had on the bike over stock form.
While they may look different on the outside, few internal changes exist between them despite being almost two decades apart.
The most obvious change on the outside of the bike is the addition of an R-Tech restyle kit, available through MX Revival HERE. The kit comes with a full set of plastics, as well as a new fuel tank and airbox covers. Anyone who has owned a YZ knows that having graphics stuck directly onto your gas tank is a recipe for bubbles in short order that never seem to go away, and eventually we just had enough of dealing with it. The R-Tech kit’s big improvement is changing up the side shrouds to cover the tank, eliminating the need for tank graphics and those unsightly bubbles. The rest of the kit is very similar to the 2015+ OEM style plastics, which we prefer over the recent 2022 restyle, but that’s entirely a personal preference.
R-Tech's over-tank style side shrouds are a major improvement
In the handling department, one of the biggest struggles we always had with our YZ was front end push in corners. No matter what we did we just couldn’t shake the feeling that the front tire wanted to keep going straight rather then follow a rut. After an unfortunate incident during an Endurocross race left our stock swingarm destroyed, we decided to see how one of the modern four stroke style swingarms bolted up. As it turned out, a 2009 YZ-450F swingarm will bolt right up with no modifications, however you will need the matching linkage as well. You can use the 2010+ swingarm, but just be aware that you will need to machine .150” off of one side of the linkage mount and create a spacer of equal thickness on the other side because the linkage is offset slightly. This is a mod that we think is well worth doing, the 450 swingarm is slightly longer than the two stroke version which helps put a bit more weight on the front end of the bike while cornering and reduces some of the tendency for the front end to push. It also has the added benefit of looking a lot more modern, and does not require the rubber plugs that cover the linkage mounting bolt.
While the swingarm mod did make a noticeable difference in the handling of the bike, we still had issues with front end push. After talking with our friends over at Luxon MX, they recommended switching to a 22mm offset triple clamp from the stock 25mm offset. Let us just say that these Luxon clamps are truly works of art, the quality of the finished parts and the amount of in-depth analysis that went into their design is truly revolutionary for this industry, and blows any other aftermarket clamps away. Not only did we get the offset change we wanted, but we also saved almost 1lb of weight over the OEM clamps! On the track the 22mm offset was a major improvement, why the stock YZs still come with the 25mm clamps is truly a mystery to us as the reduced offset is a major improvement. With the clamps and swingarm mod the bike finally tracks through corners the way we like, and the front end push we struggled with for so long is all but gone. We also bolted on a set of ignition and clutch covers to give the bike some added protection, and a fresh look.
Clamps can be found HERE
Ignition cover can be found HERE
Clutch cover can be found HERE
In case you couldn't tell, we're big fans of Luxon products
When it comes to suspension the YZ is pretty good in OEM trim. The KYB SSS suspension is decent, not the magical wonder that most magazines and message board posters make it out to be, but it does everything acceptably well. Over time as we got a bit faster, we realized that the stock suspenders just weren’t cutting it anymore and it was time for an update. While we could have just revalved our stock stuff, we wanted to keep it as is to use for trail and endurocross riding and have a second set of suspension that we could stiffen up for the track. We decided to order a low hour set of forks from a 2008 YZ-250F off Ebay, opting for the four stroke version so that we could use the leaf spring style mid-valve rather than the coil spring style found in the two stroke forks. While these forks are about 5mm longer, we just compensated for this by sliding them up in the clamps a bit higher. After riding with the stock settings a bit we decided to stiffen up the mid-valve to help keep the fork up in the stroke, and this seemed to help the front end react more consistently. We’re still testing and tuning, but overall we have the forks working much better than the OEM stuff did for us.
A fresh set of forks was a major handling improvement
Turning our attention to the rear shock, we really scored with a full custom setup from a friend of ours at Fox Shocks. The biggest change between this custom Fox shock is the use of a floating piston rather than a bladder in the reservoir, as well as a check valve on the top of the shock shaft to isolate the compression and rebound circuits. When you make rebound changes on a standard shock this will also affect compression since the rebound needle acts as an oil bypass, making tuning a bit frustrating and confusing. With the isolated rebound circuit, we can make changes one at a time without having any spill over into other aspects of the shocks performance, making tuning much easier and straight-forward.
Would you just look at it. . .
At first we found that the shock was on the soft side, so after stiffening up the valving a bit and running the high speed compression cranked in a little further we had the bike much more balanced out. Suspension tuning is always a process, but we’re getting closer and closer to our ideal setting and learning a lot in the process. We always dreamed of having a set of A-kit suspension on our ride, and this shock fits the bill!
The final major modification from stock will be a bit controversial with the moto-only crew, but we swapped out the stock 19” rear wheel with a more offroad-oriented 18”. We ride a mix of moto and offroad, and for us the 18” is the best compromise in performance. Although heavier, we really enjoy the taller tire sidewall on both the track and trail and feel that for the average rider the 18” is probably a better option than the harsher 19”. This also gives us the opportunity to run more offroad specific gummy tires for Endurocross events, which often aren’t available in 19” sizes.
The 18" rear is a necessity on the trail
On the track or trail, the 3DP YZ really is a blast to ride. With the updated looks and improved chassis geometry, this is the bike that we wish Yamaha would have released in 2022. It would require no changes to the existing chassis, and the swingarm tooling already exists from prior YZ-450F production runs. The improved 22mm offset clamps would also be a very simple change, and combined with some motor updates it would really bring the bike into the current decade to compete with the orange brigade. One day maybe Yamaha will do a true revamp of the YZ line, but until then we’ll just have to enjoy the solid foundation that these bikes provide and the plethora of aftermarket and NOS options available to keep them riding strong.