Need advice to help my brother out

My brother bought a WR450F. He wants it to run without backfiring, boiling over and getting beat by my CRF..... time to uncork the WR and unleash the beast. He's not too mechanical, so he asked me to do the usual mods for him. I don't know Yammy's but I've done the airbox, grey (pink for honda) wire and JD jet kit on my bike.

Here's what I'm planing for his WR:

1. open airbox

2. JD jet kit

3. Bigger pilot jet (any suggestions for 1300 ft ASL)

4. Grey Wire

5. Rad guards, skid plate, Bark Busters

Am I missing anything?

Thanks for your help

You're a nice brother.... :applause:

How about pull the insert out of the exhaust? That'll to wonders....

After market exhaust is the best change I ever made to mine, then jetting the bike for it. I wouldn't recommend opening the airbox too much, for this allows a lot more debris to enter the airbox unless you ride in a nice clean place. As for the backfiring and boiling over it sounds like the bike is lean.

The first thing I would do is cut the throttle stop screw down so it is not using only half the throttle. That will make the biggest change and tell your brother to get a mirror so he can see you eating his dust.

Replacement fuel screw to adjust it on the carb would be nice. See the jetting guide that is stickied in here, I believe, for which jets to use based upon altitude and temperature.

what year is it?

if it is an 05+, then a few more things need to be done, aside from the requisite throttle stop, airbox, grey wire, muffler insert.

The carb is also plugged up a bit. Remove the float bowl and knock the plug out of the fuel screw hole so you can get to the fuel screw...while you are at it, replace the screw with ZipTy screw. can you believe the number of times i used the word "screw" in that sentence?

Then, pull the needle and replace it with an adjustable needle...like the JD.

also, if it is an 05, an AIS removal kit would be a good idea. You can get them, along with the screw and jet kit from the TT store.

oh, and pick up the afformentioned mirror too...hes gonna need it.

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