FX350 - Suggested Mods for trail riding and trail blazing?

Hi guys, 

I have the opportunity to get a new 2017 FX350.  I really like what I've read about them so far and I think they look awesome.

I have never owned a 4 storke dirtbike, only two strokes.  My last two bikes were a 2006 YZ250 (set up for woods) and 2013 KTM 300XC-W.  They have since be sold as I want to try a four stroke.  

I do understand that the FX is purpose built for closed course racing and is basically an MX bike with a few changes.  That said, what mods should I make to the FX350 to make it an enjoyable and easier bike to ride on trails and trail blazing?  As of now, I guess my biggest concern is flame outs while riding slowly.  From what I gather, that's an issue with the FX bikes.  

So, where should I start in my effort to convert the FX350 into a woods bike that is as forgiving as the 300 2T?

 

Thanks for you help! 

 

 

 

  

Edited by chris818

You don't have to change anything. That's already an excellent woods machine in my opinion. I ride an fc 350 in the woods and absolutely love it. However, if you've ridden exclusively on two strokes, four takes some getting used to. Specifically for me was the engine braking. My first competitive 4T was a 450 and I've found the 350 has much less of a will to launch you over the bars than its big brother. FX 350 is a trail blazing dream bike straight from the showroom floor dude. I dropped a tooth on the front sprocket and don't have flame out problems at all.

 

 

Put a 13t on the front and adjust idle would be my first mods... The bike becomes 3x more manageable once you do that... 

i did 13t and raised idle to about 1200 and i love it. i do wish it was 50lbs lighter at time lol...

Thanks for your responses guys.  Yes, I imagine, riding a four stroke of this caliber would take some getting used to.  I've never ridden one, but have ridden high performance 4T quads which had a helluva a lot of giddy up, in a different way than my 2 strokes dirtbikes and quad.

The gearing and idle are a great and simple starting point.  I'm a big guy - about 240lbs.  Do you think just changing to a 13T on the front would be enough or should I add a tooth or two to the rear?  

 

Thanks! 

 

 

Quote

 

 

Edited by chris818

At 240lbs, spring and a possible revalve is needed.

7 hours ago, weantright said:

At 240lbs, spring and a possible revalve is needed.

Yup, a heavier spring for sure.  

Any thoughts on the Reckluse 3.0?  Naturally, I'll ride it as is, put some hours on it and figure out what is actually necessary for me.  Again, biggest concern is stalling when in a compromising position ie: a steep climb or decent.  I'll figure it out. 

 

Thanks guys! 

 

I did a 12 on the front. It'll most likely wear out the chain a bit quicker than usual, but I can let out the clutch and just idle along. Been very helpful for teaching the kids for one thing. I've got a buddy that pushes the scale at 320, and he rode it before I even changed from the stock 14 and it pulled his butt around no problem.

 

20 hours ago, chris818 said:

Thanks for your responses guys.  Yes, I imagine, riding a four stroke of this caliber would take some getting used to.  I've never ridden one, but have ridden high performance 4T quads which had a helluva a lot of giddy up, in a different way than my 2 strokes dirtbikes and quad.

The gearing and idle are a great and simple starting point.  I'm a big guy - about 240lbs.  Do you think just changing to a 13T on the front would be enough or should I add a tooth or two to the rear?  

 

Thanks! 

 

 

 

As others have said, you'll seriously want to consider stiffer springs.  I'm assuming when you say 240lbs, that is without gear? If so, you can easily be 100lbs over what the stock suspension is set up for.  That's 4-5 spring sizes on the rear.  Not sure on the AER front how many sizes.  You'll notice a lot of softness and bottoming out of your stock suspension, which will make for a very rough ride. 

Edited by markbfe501

Im 225 lbs with gear and went up to the 4.7 husqvarva spring in the rear.

And also at 148 psi in front fork. 

Also went 13 tooth, spark arrestor, grunt valve and fuel rail kit from Ktm and Husky out of Arizona. 

What is a "grunt valve"? Sounds like a "pull my finger" joke.

Here it is, a exhaust flange machined smaller to improve low end performance. 

 

be4f25_42e83d5ab91a4a00ad01e9fe521a72a2-mv2.jpg

Did you notice an improvement in low end performance?

3 hours ago, Russell Kinsey said:

Here it is, a exhaust flange machined smaller to improve low end performance. 

 

be4f25_42e83d5ab91a4a00ad01e9fe521a72a2-mv2.jpg

Interesting.  I installed a custom-made 3mm thick pipe spacer on my old 2006 YZ250.  Same concept, and yes, it did add to the bottom end. 

 

15 hours ago, chris818 said:

Yup, a heavier spring for sure.  

Any thoughts on the Reckluse 3.0?  Naturally, I'll ride it as is, put some hours on it and figure out what is actually necessary for me.  Again, biggest concern is stalling when in a compromising position ie: a steep climb or decent.  I'll figure it out. 

 

Thanks guys! 

 

Rekluse is nice and in many places is worth it however at the cost I would first try adjusting the TPS and raising the idle. Then again if you have the money then do all three, Rekluse, TPS and idle.

 

I personally wouldn't go 12t but 13 and adjust the rear accordingly to your terrain. Too small of a sprocket wears the chain as post above, slider and counter sprocket/seal.

KTM and Husky.com,,, While they may have some products that do work, they also sell open hart surgery for simple hart burn. After talking to them in the past I would never support them again, unprofessional and shady.

Rekluse is a bit too proud.  I have one on my YZ, and I really like riding with it, but they were way less expensive back when I got that.  It's hard to cough up a grand for a fancy part that just helps feather the clutch.   Stick with a 13 tooth and you'll be plenty happy, even with the stock 14, you'll dig it.   I am really interested in that exhaust spacer thing.  "GRUNT VALVE"...  sounds like a custom toilet bowl attachment...

5 hours ago, weantright said:

KTM and Husky.com,,, While they may have some products that do work, they also sell open hart surgery for simple hart burn. After talking to them in the past I would never support them again, unprofessional and shady.

Seems like a bit of snake oil...  Some of that stuff anyway.  Hey Russell Kinsey,  do you have this spacer?  What about that fancy aluminum tube thing?  https://www.ktmandhusky.com/power-intake-tube-foe-2017-exc-fe 

6 hours ago, weantright said:

 I would first try adjusting the TPS and raising the idle. Then again if you have the money then do all three, Rekluse, TPS and idle.

 

Futzing with the TPS to fix the flameout problem is not the correct fix on the FX 350. It's a bandaid at best and will completely screw with the fueling at worst. Do it right and get an FI tuner (like the JD Jetting Power Surge) if you want to add fuel to address the flameout issue. 

 

Edited by SquidZip

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