FE/FC Holes on your left side cover (airbox airflow)

have a thread in the 2 stroke section, so here for you 4T guys
http://motocrossactionmag.com/news/ask-the-mxperts-how-to-make-a-husqvarna-breathe

http://www.cafehusky.com/threads/drilling-holes-in-airbox-cover.45245/page-3#post-549803

The MX action article seemed to imply that these holes helped the low-end and midrange power. Is that what you experienced? I thought something like this would only make a difference at high RPM.

Definitively helps with the low end stall and low and midrange power. I could be wrong, but my theory is that at low rpm low speed the stagnate air in the enclosed box gets hot and I call it "stale".
I used to have this almost stall after pulling out a technical bit where the bike would idle for a few seconds, with the holes in the cover that issue is totally gone.

I drilled a couple of holes in mine and used the uni plugs but had not seen these threads. Now I don't think I've done enough!!! Think the drill needs to come back out!!

I've always meant to 'test' with the sidepanel off too but never got round to in. That will happen very soon too.

Great info in there.

note addition see the other thread the factory race team bike do not have side panel holes of course but those trick CF subframes are fully open through those triangular "grab" handle holes, so there is where the race bikes breathe from

after inspecting a new on the showroom FE501, I really think that we can remove some material in the "handhold" (which is really the airbox opening port.) there is a "wall" of plastic that does not appear to be structural webbing, the seat force is tied directly into the down spar that attaches to the frame.
I just got 2016 side panels and would prefer not to hole saw my left cover. I will have a real good look at my machine later to see if I want to pin rout that material off to allow airflow.
PS realize that these bikes are street homologated in EU and must comply with sound and emissions, look at the EU spec jetting for example its super lean but can still run ok due to the closed off airbox and the recommendation for 60:1 mixture also backs the emission standard to cut down on 2 stroke smoke along with reducing intake noise to comply with noise regulations.

I did a thorough inspection....there are various ribs that can be radiused to allow more airflow through the "handholds" (fake air duct openings).
These already do have openings and feed the airbox, but also have a molded in "rib walls". I would not be comfortable doing a guinea pig experiment for more airflow, only to find my sub frame going into fatigue failure.
The holes in the left side air box cover will have to do.

I drilled mine and can honestly feel the difference in roll on power and the tiny bog at 1/8 throttle is gone. But, I turned up the idle a bit as well so I'm not very scientific. Runs better for sure. May not need to adjust TPS now but will check it when the brown truck delivers it. Pictures are too large to put here but I drilled 3 holes from 1 1/4" down to about 3/4" just under the seat on side cover. Third Huskie I've drilled.

Man was I surprised to see my TPS was factory set at .43. I'll test this weekend if weather works out. Seat of the pants down the road was too rich at .68, better at .65 so I now have a base to work with. The Best Dual Sports box is great and zeroed for easy TPS fun. Throttle response is noticable right away but I need a familiar trail I know to really test the adjustments.

Here is the proof of the open architecture of the race teams CRM CF subframe assy. This thing breathes!! Also note I have more post op pics up in the 2 stroke section.

I cut a large hole in my airbox cover and can definitely feel a difference in smooth, low to mid end power. I got a screen repair kit from the hardware store and epoxied it to the inside of the cover.

Think I have just picked up a used Carbon rear subframe looking forward to fitting that once it arrives. The joys of the 15 parts not fitting the 16 model

Dirt Rider E-Cross build 2015 FE250 for Kris Keefer.

man that will suck in small animals!! I think I would really add some sort of screen just to be.....I don't know just to make it look sort of "factory"