There are several modifications that can be made to your CRF450X to overcome the limitations of the stock exhaust system. For instance, installing the Demissions “PowerBack” Kit from F2Racing.net is a great way to boost your CRF450X’s performance. Along with increasing horsepower and cooler running temperatures, the kit will also eliminate the popping from the exhaust that often occurs during deceleration. The Demissions PowerBack Kit will also give your bike the benefit of a 1.5 pound overall weight decrease.

Another highly effective and easy to install solution is the White Brothers E2 exhaust slip-on. It’s a one-piece unit made from aircraft grade aluminum alloy. While the mid-pipe and inlet are made of stainless steel, the mounting bracket is made from billet aluminum. The E2 slip-on provides significant performance increases in the low and mid range with notable gains up top, and the throttle response is improved dramatically. It creates a nice tone while still remaining within the boundaries of the U.S.F.S. 96 db rule. Although it extends a bit farther than the stock exhaust, it doesn’t interfere with riding and it only weighs 6 pounds and 6.8 ounces (nearly two pounds less than the stock exhaust).

The CRF450X is an incredible bike with tremendous power, speed, and maneuverability. The exhaust is just one aspect that can be modified to make it perform that much better.

Related posts:

1. Exhaust Options for the CRF450X – Part 1
2. F2Racing.net Demissions “PowerBack” Kit for the Honda CRF450X
3. R&D Flex Jet Remote Fuel Screw for CRF450X

The kit contains the following items;

1. Stainless steel tweezers, for pulling the new screw top and needle out, if you have to make changes
2. Slavens racing adjustable fuel screw
3. new leak jet
4. new adjustable needle, which is a factory kehien needle race needle
5. new screw top for the slide to secure the new needle
6. Air injection block off, correctly shaped to match the exhaust port
7. 2 – billet air box plugs
8. stainless allen accelerator pump cover screws
9. stainless allen float bowl screws
10. stainless allen fuel spigot screw
11. stainless allen intact tract block off screw

The kit is available for all years of the CRF450X including 07. For 07 Honda changed the needle design and it requires a little different setup so be sure if you order the kit you get one for the correct year.

The most unique thing about this kit is the air injection block off. It’s correctly shaped to match the exhaust port on the CRF450X head and according to the manufacturer the bike will run cleaner and crisper with the fitted piece as compared to an ordinary unit.

They warranty the workmanship and that everything will fit right.

According to Dirt Bike Magazine “The Power Back kit should be the first thing you buy for your bike!”

F2Racing.net also has other items that will be available for the CRF450X soon, we’ll let you know when we see them.

Related posts:

1. R&D Flex Jet Remote Fuel Screw for CRF450X
2. Honda Bulletin for 2005 CRF450X Closed Course Competion Modifications…
3. Honda CRF450X dry weight

So here we go, directly from the bulletin……..
2005 CRF450X
Competition Use Only

It is the dealer’s responsibility to investigate any potential law violation pertaining to these modifications. You should refer to the procedures based on a customer request to ride the CRF450X in closed course competition only.

To increase performance for closed course competition use only, follow the steps below. You must make all of the changes to gain more performance.

1. Confirm the customer will be racing the CRF450X on closed course race circuits such as motocross tracks where they will not be violating noise or emissions regulations.

We recommend you write the following or similar text on work order, sales invoices, or parts receipts:
Customer understands parts installation and performance modifications are not emissions or noise compliant and are for closed course competiton use only. Riding in non-competition, non-closed course setting may result in the customer receiving fines or penalties for vioulation of noise limits or exhaust emission laws.

2. Replace the standard CRF450x camshaft with a CRF450R camshaft.
-Camshaft
P/N: 13110-MEN-670, H/C: 7530843

3. Replace the standard CRF450X exhaust header pipe and protector with CRF450R parts. Also replace the exhaust gaskets.

-Exhaust Header Pipe
P/N: 18320-MEN-730, H/C:7819618

-Exhaust Protector
P/N: 18323-MEN-730, H/C: 7819626

-Exhaust Gasket
P/N: 18291-MEB-670, H/C: 6844559

4. Replace the standard carburetor parts.

-Main Jet (from #142 to #162)
P/N: 99101-357-1620, H/C: 0419200

-Jet Needle
Change the clip position from #2 to #5

-Leak Jet (from #70 to #65)
(Accel. pump bleed)
P/N: 99108-KSC-0650, H/C: 7660558

5. Set the pilot screw to 1 3/4 turns out.

6. Remove the diffuser pipe from the muffler.

7. Increase the airbox opening as follows:

-Remove the subframe and airbox.

-Drill out the two pop rivets holding on the air snorkel and remove it.

-Cut othe section shown inside the raised cut line while wearing eye protection.

-Reinstall the airbox and the subframe.

9. Behind the left side cover there is a “natural” color main coupler. On the ECU side of this natural coupler there is a Pink wire. Underneathe the Pink wire is a blank terminal plugged with a rubber cap.

Swap the positions of the Pink wire and the rubber cap. Reconnect the coupler to the wiring harness. (In modified form, the Pink wire is NOT connected to any other wire.) For more pink wire information click here.
10. Remove the noise and emission compliant label from the rear fender.

Remind the customer these modifications are for closed course competition use only.

There you have it!!

Related posts:

1. Finally some real logic on what the pink wire mod for the CRF450X does.
2. 2005 Honda CRF450X Development
3. 2005 Honda CRF450X Features