2017 Husqvarna FX 350 Project Build


This article was originally featured in the September 2017 print edition of Dirt Rider.

Everyone wants a do-it-all machine. A bike that can blip through a motocross track rhythm section, seamlessly peel off onto some single-track, and whiz through the trees then grab a couple of gears and tear across the open desert. While that track-trail-desert combo doesn’t exist, that bike doesn’t exist either... But there is one that is close. We’ve explored this topic previously in the May 2016 issue with “The Everything Bike” that made a KTM 350 XC-F both a moto and off-road machine. This time we took a less invasive, more budget-friendly approach to making our 2017 Husqvarna FX 350 a better all-around ride.

Husky’s FX line of motorcycles is already claimed to be somewhere between moto and off-road. At the bike launch last summer, we rode at Cahuilla Creek MX on both the motocross track and single-track trails in the back of the property. After a day on all of the FX/TX models, I personally wanted to spend more time on the FX 350. What stood out to me was how versatile the bike was. I know it’s cliché by now, but the 350 really has the best of both 250 and 450 four-stroke motors, plus with the latest version of the Husky/KTM chassis that has an incredibly light, slim, and agile feel, it was so much fun that I just wanted to ride it more.

For moderate trail riding and slower technical stuff, the suspension was set up pretty well from the factory, yet for faster trails, moto, and for my weight (215 pounds) I needed it stiffer. That being said, before the bike was shipped off to Race Tech for it to work on both the suspension and motor, I raced the Adelanto GP on this bike pretty much stock. In the endless sand whoops and short EnduroCross-style section, it was very evident that I needed more hold-up from the suspension and that a little more snap from the motor to get up and over obstacles would make life easier.

The simple and most common way to get quick power from a bike is to slap on an aftermarket pipe, but I was very happy with the quiet exhaust note from the FX 350’s stock muffler. Also, full exhaust systems can be close to, or more than, a grand. Race Tech’s Engine Services Department does motor work, and I decided to have it do a five-angle radius valve job with full porting. Rather than putting in a bunch of aftermarket parts, Race Tech reshapes the valves and valve seats and reshapes the intake and exhaust ports all with the aim of increasing flow and maximizing efficiency without sacrificing durability.

Once I got the bike back and hit the trails, I didn’t notice a major difference right away because, one, it didn’t sound any different, and, two, unlike a pipe, the porting didn’t shift the power around; it increased the power across the board (where an exhaust system might give you more bottom-end at the expense of top-end power). After pointing the FX up some of our “butt-dyno hill climbs,” it was very noticeable that the engine work gave the machine more pulling power as I easily cleaned some steep grades the stock engine struggled with. Again, there isn’t a big hit anywhere or increase in one section of the power. The engine character remains the same. I like to think of the 350 now being sneaky fast. You don’t hear more pop, but you feel it and notice that you are just riding faster and needing to twist the grip a little less to do the same things. All without increasing decibels.

Along with getting a stiffer rear spring (4.8 kg/mm from 4.3 kg/mm) and Gold Valves in the shock, I asked about Race Tech’s spring conversion kit for the WP AER fork—not that I didn’t like the AER fork, just that it was on the soft side for me and, to be completely honest, for an off-road bike with long rides in its future, I didn’t want to mess with air pressure building during the day or setting it every time I rode. Also, I was just curious about how the spring conversion kit works in the WP unit.

At first, the shock seemed too stiff and the fork too soft. This is because I’m used to riding stock bikes with shock springs that are too light for me. After playing around with the clickers, I ended up at two clicks stiffer on the fork compression, a quarter turn softer on the shock high-speed compression, two clicks softer on low-speed compression, and two clicks stiffer on shock rebound. After these minor changes to get the back end a little lower and more settled and the fork to stay a little higher in the stroke, the bike was dialed and balanced. The harder I rode it, the better it felt, especially through rough, fast trails.

While the stock suspension had comfort, it moved a lot (pitching on braking and acceleration). The Race Tech suspension kept the bike more even and planted and gave the bike a more neutral “dead” feeling that let me push much harder and not have to back off the throttle when coming up on trail chop or deep whoops. The only issue I was having was the front pushing a little in tight turns on the motocross track. Given more time, sliding the fork up a little in the clamp probably would have been my next move.

If I truly wanted to go stealth mode with this project, I should have left the stock plastics on it, but when I saw Acerbis’ Flo-Yellow plastic kit, I couldn’t help it. While the bike sounds stock, it certainly doesn’t look like it. I was very happy with the way all the plastics bolted up just as seam­lessly as the stock pieces. I left the graphics up to DeCal Works. The guys there asked me to ship them the plastics so they could apply them (which is out of the norm for us), but the reason was that a majority of the graphic is clear, which will show every little bubble and even fingerprints, so application is especially tricky. As for the Acerbis X-Seat, the thing is grippy as all get out and helped me stay on the bike up some tough hills better than any stock seat has.

Overall, this project build made me sad. That’s because after it was done, it rode sweet, looked sweet, and sounded quietly sweet, but ultimately we had to give the bike back. My only regret is that we didn’t build it sooner.

What’s Hot

  • More power across the board
  • Better balance and more consistent suspension
  • Looks that turn heads

What’s Not

  • Still doesn’t rip off the bottom
  • Budget-minded builds can still add up in costs

Michael Allen Age: 30, 6’0”, 180 lb. Off-Road Expert

The Husky 350 project bike went in the right direction in terms of making an off-road racebike. The Race Tech suspension was a good combination of supple and firm, having the ability to eat up small chatter while staying up in the stroke. When I rode the bike, the sag was not set for me, so the front end had a slight knifing feeling, but I’m sure with the correct sag it would have been better. The engine felt a bit like it wanted to be ridden in the higher rpm range but still had the ability to be lightly lugged without flaming out. I’m not sure if I’m a fan of the neon plastics, but it definitely stands out when it’s in the pits.