2006 TRX450 info

[motoz/HMF]

The Honda TRX450 is in the same boat as the Yamaha YFZ as the carb is really lean from the factory.

**It has a D shaped fuel screw, that with the trick Motion Pro 90* tool it is still hard to adjust.
**It has a NON ADJUSTABLE NEEDLE.
**The air box lid is super restrictive for ANY mod you will do. EXPECT to run without it or cut BIG holes in it.

The main problem is the needle, with the lack of adjustment we are losing power in the 1/4 to 3/4 throttle position or 3,000 to 6,500 RPM range.
We are working to get an adjustable needle for more testing when I get that I will post the dyno powercurves, we should have a needle in a day or so.




***CLICK BELOW TO VIEW THE INSTALLATION INSTRUCTIONS OF THE SLIP ON/SYSTEM AND NEW HMF NEEDLE INSTALLATION INSTRUCTIONS
http://hmfengineering.com/forums/showthread.php?t=1150

[motoz/HMF]

Thanks EPA !!

[motoz/HMF]

C'omon a BIRD couldn't breathe through this thing !!!

[motoz/HMF]

Gasssssp! I need AIR

[motoz/HMF]

Getting the numbers..

[motoz/HMF]

We have treid several adjustable needle combinations and have found one that makes up the loss at the 3~6k RPM range because the stock needle is NOT adjustable.
**This needle will be available from HMF for $9.99


NOTE:
Because of the extremely restrictive airbox lid the slip on and full system runs were done with the LID OFF.

Baseline jetting for a full system:
Fuel screw 2.5 out.
Pilot:48.
HMF needle 3rd clip from the top.
Main Jet: 165.
Aftermarket filter may require a 170~175 main jet.

Baseline jetting for a slip on:
Fuel screw: 2.5
Pilot jet: 45~48
Needle: HMF 3rd from the top.
Main jet: 160~165.
Aftermarket filter may require a 170~175 main jet.

NOTE:
These settings are a baseline for which you can do further tuning for your location and conditions.




The stock backfire screen is another bad point in the intake tract.
It restricts the top end flow and "full throttle grabs", until someone comes out with a different intake set up you will NOT get the 1~1.5 HP gain on top.

When one does become available you WILL get the power.

We took our backfire screen to the plazma cutter and removed 90% of it for testing and it DID add the power back to the top and bottom. WE DO NOT suggest you mod yours like we did, it may suck the foam filter into the intake.

BLUE: is an all stock run. 32.4 HP
RED: is a HMF full race system with the new HMF needle. 36.4 HP
GREEN: is a HMF full race system with the stock needle. 36.2 HP