2017 Husqvarna FX 350 Project Bike Build
This build is very doable for the weekend warrior.Photo by Drew Ruiz

Over and over I find myself really digging a four-stroke motor falling between the standard 250 and 450 sizes. Husqvarna offers a few middle-weight machines and the one that caught my eye was the FX 350. Also sort of in between motocross and off-road, the “cross country” FX is meant to handle both track and trail duties alike. I called dibs on it at the press intro and I’ve had since. I’ve taken it to the track, to our usual off-road stomping grounds, and raced it at the Adelanto GP, all while leaving the bike pretty much stock. Fortunately and unfortunately, I didn’t really have any complaints (un- because with nothing to fix, a project build has little direction), other than the stock suspension being a bit soft for my weight and riding style, and perhaps wanting just a touch more snap/excitement from the motor. I guess we just have to get greedy sometimes. Well, Race Tech came in to save the day with both their suspension work and their newly offered engine services.

2017 Husqvarna FX 350 Project Bike Build
The Flo Yellow Acerbis plastics were completely unnecessary, but also completely awesome. Hi-viz Husky? Heck yeah!Photo by Drew Ruiz

Starting with the suspension, the WP AER fork is a pretty impressive air fork… Actually, it’s a good fork all around, regardless of its spring situation. I really only have two complaints: One, while the comfort level was super high, the performance level didn’t match. I wanted a little more hold up on big landings and hits and if I used air pressure to reach that desired firmness, I lost some of that initial plushness that my wrists crave. Two, I don’t like messing with air pressure in my fork. It’s not a lazy thing (well, not wholly a lazy thing), its more about being mentally concerned about pressure build-up during long off-road rides and knowing that there is always a slight variance in air pressure when you take off the gauge because you lose a little bit but how much you lose is dependent on how fast you unscrew the Schrader valve.

2017 Husqvarna FX 350 Project Bike Build
I mostly rode the 350 in fast, flowing trails with some techy stuff sprinkled in.Photo by Drew Ruiz

With the AER Spring Conversion Kit installed, as well as their Gold Valves, the fork was initially too soft. I was riding too low in the stroke and I added two clicks of compression and found that made a big difference. The Gold Valves let a lot of oil flow through which enables the fork to stay soft when you want it to be, at the top of the stroke an on sharp hits. But the spring added consistency and controlled firmness that I really liked. The shock also got a revalve with Gold Valves and a new, much stiffer spring (4.8 kg/mm from 4.3 kg/mm). If you fall outside of the 160 to 180 range, do yourself a favor and get you bike resprung. Having the stiffer spring in the rear balanced the FX out and let me ride harder, faster, and with more confidence. Setting sag is important but can only get you so far. With the Race Tech suspension, I didn’t have to back off when the trial turned to endless whoops and it helped me turn the machine easier because of the proper weight distribution.

2017 Husqvarna FX 350 Project Bike Build
Race Tech did a full port job and five radius valve work.Photo by Drew Ruiz

Moving on to the motor. Stock, the power is plenty to have a great time on the track or in the woods, yet the the bottom end is on the smooth mellow side – it likes to be revved out more than short-shifted. Race Tech’s engine work included a five angle valve job and full porting of the head and rather than shifting the power around it boosted the power across the board. At first I didn’t really notice because it sounded the same (nice and quiet) and there wasn’t a big noticeable hit. But after a few hill climbs and loops on our usual testing loop, I noticed it was easier to ascend and I didn’t have to rev out the bike as far in certain sections. If I was really desperate for more bottom end excitement, the next step would be a pipe.

2017 Husqvarna FX 350 Project Bike Build
With the proper springs for my weight, the bikes balance, and therefore handling, was greatly improved.Photo by Drew Ruiz

The other fun bits on the build are less performance, more protection and preference. I’ve been a fan of the ARC Memlon levers since they came out for both their “bend, don’t break” operation and the wide feel at the finger. The FX 350 has the coarse versions which has a raised diamond pattern for better grip in wet and muddy conditions. I didn’t find much moisture to test this but I can say that there is definitely added grip – so much so that if you run super minimalist gloves, your lever pulling fingers might be a little raw after a full day of aggressive clutching. The Acerbis X-Seat is waterproof so no need to take it off when you wash it. It is a little heavier than stock, but it is nice and firm and has a unique square-ish feel that I liked. It is also super grippy. It saved my bacon when climbing a steep, long hill when both my feet came off the pegs when I misjudged the last ledgey section. I squeezed with my upper thighs and glutes (mostly involuntary) and I didn’t slide an inch and cleared the hill.

2017 Husqvarna FX 350 Project Bike Build
While we didn’t get to ride it that long in its fully build form, the DDC steel rear sprocket is very light for piece claiming to last 100 hours. We also got a fresh RK 520EXW chain.Photo by Drew Ruiz

To keep the bike from getting too banged up, I put on some Bullet Proof Designs Radiator Guards. These dark blue aluminum pieces are pretty burly and they mount up just the same as the plastic stock louvers, just using longer bolts (supplied). They are also a little heavier than stock but I trust them much more than plastic. Out front I put on a System Tech Racing Front Rotor Guard. Rather than bolting to the fork guard mounting points, this guard replaces one of the wheel spacers and “floats” between the rotor and the fork leg. Also, it super light and very stiff. Where standard plastic covers would bend and make contact with the rotor, the STR guard’s carbon fiber piece is super thick and has zero give. The outer edge is covered in replaceable plastic if it gets too chewed up. I threw on a tried and true Enduro Engineering skid plate but added their new Linkage Guard. It is a pain to install onto the skid plate but some scrapes and gouges in it told me it was doing its job. Lastly we freshened up the drive train with a DDC steel rear sprocket and RK 520EXW chain.

2017 Husqvarna FX 350 Project Bike Build
The X-Ultimate hand guards are simple flag type guards good for brush, roost, and rocks, not so much tree trunks or branches.Photo by Drew Ruiz
2017 Husqvarna FX 350 Project Bike Build
This is one off-road bike that didn’t make me avoid flat landings.Photo by Drew Ruiz

To be honest, I was super bummed to have to give this bike back to Husqvarna. I had spent a lot of time on the bike and with the suspension and engine mods taking it to the next level, I wanted to get a lot more racing in. Also, it was an awesome feeling riding a bike that had better power than stock while using the stock muffler and keeping the sound and price down. If there was one more mod I would make, it would be to swap the stock battery for a smaller lithium unit. Obviously lighter, we’ve also heard that it increases the air box volume and might give the Husky a little more snap.

2017 Husqvarna FX 350 Project Bike Build
The stock spring is 4.3 kg/mm and Race Tech installed a 4.8 kg/mm for my girth and faster GP style riding that the bike was slated for.Photo by Drew Ruiz

What’s Hot:

  • More power across the board
  • More performance from the suspension
  • Looks that turn heads

What’s Not:

  • Still doesn't rip off the bottom
  • We had to give it back
2017 Husqvarna FX 350 Project Bike Build
The engine mods offered improved performance without raising the decibels or costing as much as a full exhaust system (that is, if you do the disassembly/rebuild yourself).Photo by Drew Ruiz

Parts List

  • Bullet Proof Designs Radiator Guards: $219
  • DDC Rear Sprocket: $110
  • RK 520EXW Chain:
  • Enduro Engineering Skid Plate: $109.95
  • Enduro Engineering Linkage Guard: $44.95
  • Acerbis Full Plastic Kit: $164.95
  • Acerbis X-Seat: $199.95
  • Acerbis X-Ultimate Handguards: $39.95
  • ARC Black Coarse Levers: $69.99 each
  • System Tech Racing Front Disk Guard: $149.95
  • Metzeler MC360 Mid Soft Tires: $See your local dealer
  • Race Tech Suspension Work

  • Fork Revalve Labor: $100

  • Fork Remove/Re-install Labor: $50
  • Gold Valve Fork Combo Kit: $179.99
  • Fork Spring Conversion System: $499.99
  • Hi-Performance Fork Spring at a .96kg rate: $94.99
  • Shock Revalve Labor: $100
  • Shock Remove/Re-install Labor: $50
  • Ultra Slick Suspension fluid: $24.99
  • G3-LD Shock Gold Valve Kit: $169.99
  • Hi-Performance Shock Spring at 4.8kg rate: $119.99

  • Race Tech Engine Work

  • Dyno/Tune: $200

  • Five Radius Valve Job and Full Porting: $575
  • Decking: $65
  • Engine Disassembly/Rebuild and Hone: $300

  • DeCal Works Graphics: $268.95

  • Pro Taper Race Cut Grips: $9.99
2017 Husqvarna FX 350 Project Bike Build
For looking so weird, the X-Seat felt pretty good. A little more square feeling under your butt, but it wasn’t uncomfortable and had excellent grip.Photo by Drew Ruiz
2017 Husqvarna FX 350 Project Bike Build
The ‘floating’ front disk guard from System Tech Racing is a beefy unit. It replaces a wheel spacer and is as easy to ‘bolt up’ as putting your front wheel back on.Photo by Drew Ruiz
2017 Husqvarna FX 350 Project Bike Build
Radiator Protection (and a bit o’ bling) from Bullet Proof Designs.Photo by Drew Ruiz
2017 Husqvarna FX 350 Project Bike Build
Enduro Engineering had the bottom of the FX 350 covered with a skid plate and new plastic linkage guard.Photo by Drew Ruiz