04 WR450F jetting

I am getting close to done with the mods on my new WR450,,,

- Exhaust insert = done

- Snorkel in airbox gone = done

- YZ throttle stop = done

And now the jetting????? and I am lost, I did read some threads on the topic and I get even more confused.

What do you guys recommend? (I am at sea level)

Rigth now I have stock jet's:

-Main #165

-Pilot #45

Pilot needle in #4.

Can I leave it stock? (would be great, looks hard ro get the carb off)

Greatful for advise.


You will need to have a bigger Main Jet at sea level. If you are backfiring you will need to change your Pilot Jet and adjust the Air Screw. If your motor stubbles during acceleration you may have to move your needle. It is a lot to think about. :cry: Go to the Jetting Forum for good info on jetting. :cry:

I, as well as many other riders, am happy with the JD Jetting kit. For cheap you could just bump up your main to 170. Maybe a 48 pilot.

Loosen both boots, and maybe remove the hot start, and you can twist the bottom of the carb out enough to remove the lower cover on the carb and access both jets. Be careful screwing in the hot start, it's plastic and will strip quickly.

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