One of the most important things to know, before just throwing more fuel to your bike is, if you take the big, dumb reed assembly out of your intact tract, as you should, you will loose a lot of intake air velocity at low throttle openings.
There is no properly shaped intake tract in the world, that makes any kind of strong bottom end power, that has a huge rectangle as it's shape. All 4 stroke intake tracts are tubed shaped, about the same diameter as the throttle body, and have a tapered entrance.
That's why we made our INTAKE TUBE. To put in the big rectangle hole, after the reeds come out, and get the air velocity back.
IF YOU JUST REMOVE THE REEDS, AND DON'T USE THE INTAKE TUBE TO GET AIR VELOCITY BACK, YOU'LL ALWAYS HAVE A LACK OF RESPONSE AND BOTTOM END. NO MATTER HOW MUCH FUEL YOU ADD.
The air is what carries the fuel into the engine. Slow air equals slow fuel equals not enough, and the motor goes BLAHHHHHHHH
The 2017 - 21 KTM EXC's and Husqvarna FE models come with REEDS, yes reeds from a 2 stroke engine, in the intake tract.
I never thought I'd see the day. Guess it's a 6 stroke now.
The reason it had to be done was to dumb down the noise the bike made, so that it could pass the drive-by sound test.
Yes my friends, since KTM and Husky decided to make 50-state legal bikes (and not 49-state “man” bikes… and 1-state “wussy” bike) all of us in the other 49 states have to suffer.
So I figured I could sit there and whine about it, or do the smart guy thing and fix it. I chose to fix it.
It's funny and pathetic at the same time, that so much work and expense had to go into putting the intake tract back to the same airboot that was stock, only one year earlier.
However, a blessing in disguise kind of situation occurred because of this and becasue what I had learned years earlier, when designing intake systems for Formula 1 cars, while living in England.
So when you remove your air filter and you see the plus shape in the intake tract, it's not KTM's attempt to rip off our SNAP airboot insert from last years bikes. It's a reed valve, from thier 2 stroke bikes, stuffed into the intake tract.
If you wonder if it's restrictive to put reeds in a normally OPEN intake tube, Heck yes it is. It's a large power sucker over last years open intake tubes. But that's the joys of worldwide emissions controls . Luckily for you, I'm more about wheelies than hanging with Prius driving Vegans, so let's eat a steak and do some wheelies.
As this picture below shows, the first thing you need to do, is cut around the glue that's holding the rubber piece in that's holding the reed cage in. The piece is just held in place with rubber cement, so cut a nice slice along the side and then jab a flat blade screwdriver in the joint and peel the thing out.
The easiest way to get the reeds out is to pull and pry. A flat blade screwdriver between the reed cage and the side of the airboot will start the removing process. Then grabbing with pliers may be the final removal tool.
By the way, there is no glue holding on the reeds. It's only the boot pressing on the cage that's holding them in place. So pry and pull and they WILL come out like in the image below.
So here is a good and intelligent question we hear sometimes...
"Why not just remove the reeds, instead of putting the Power Intake Tube in there? Are you just trying to sell us something we don't need in order to make money?"
That's a fair and good question.
And the reason is, that because the airboot around the reeds is thin, soft rubber, which means it's squishy and pliable.
So much so that it actually sucks in on itself, under the high intake vacuum of a 4 stroke.
And the larger the displacement, the higher the vacuum is and the worse the airboots sides suck in on themself.
And what happens when the airway of something is shut? Yes… a suffering for air.
Since the incoming air is what picks up the incoming fuel, and hauls it into the cylinder to make power and move you forward, both the air stream and fuel stream suffer instantaneously.
This means throttle response "lags" or "bogs".
On the left is the airboot without the reeds in it. On the right, the Power Intake Tube is in place. The tube is made of solid aluminum, and has a well shaped intake bell with a tried and true diameter and length.
On the 450’s / 500’s and 501’s, the tube sits slightly further inside the airboot than it does on the 250's and 350's (as seen in the image above).
The image below shows the tube sliding into a 250 or 350. This is how the Power Intake Tube fits on these bikes. The flat cut out on the side of the bell fits along the side of the rectangle hole, on the outside.
The small hole at the bottom serves a purpose as well, as it lets incoming air get to the intake air temp sensor.
It also serves a second purpose by allowing the air around the outside of the tube enter into the incoming airstream, to increase airflow and top end pulling power.
You’ll also notice below that the hole always points down, as the intake air temp sensor fits in the middle of the hole on the 250 and 350 models.
So that covers it!
Based on everything laid out for you on this page, hopefully you have a better understanding of air intake and what you need.
If you’re ready to get the Power Intake Tube for your bike, you can do so below for only $49.95.