[BuckNrut]

Requesting a little help. Never been much of a mechanic but I think I can do it myself. I need some tips on everything I need to eliminate the Decel Pop

Reading all of the posts I have gotten myself confused.

1-JD Jet Kit
2- Airbox Mod

Where I am confused is, do I need to also purchase a 48 main jet?

I also read where the fuel screw isnt adjustable on the 07 450X?

Do I replace the stock with CRF's only fuel screw to have one adjustable?

I am at about 1,000ft above sea level here but I guess it could vary either way by 300-400 ft depending on the area around knoxville,tn.

Can anyone de-confuse me

Thanks

[OLDFATGUY]

The 48 you refer to is a pilot jet, stock is a 45. You may need one you may not. The JD kit will come with the main jet sizes you need. The instructions are good, and you can get pleny of help from us. Not sure on the 07 fuel screw, probably just a little plug that needs removed to gain access to the screw. But it is very hard to adjust because of the space constraints. Get a CRFS fuel screw, that will make it tunable. OFG

[[email protected]]

You're on the right track bud, right on target.
There are about as many people who have tried the 48 pilot and like it as there are that have tried it and didn't, so no, I wouldn't until you have everything else in place.
You need a needle holder from an 05-06 450X OR 02-06 450R in order to install your JD needle. Install the needle just like the instructions say. This'll help you visualize a little better :
http://crfsonly.com/howto/450x/jetting/ ... needle.php
Do the airbox mod simultaneouslywhen installing the jet kit.
Get one of these, it'll make your life a whole lot easier:
http://www.crfsonly.com/catalog/product ... ts_id/1333
Make darn sure you put the stock fuel screws washer,o-ring and spring on the crfs fuel screw,and be careful pulling the old fuel screw because those parts have a way of falling out and getting lost.
I don't know if all 07 450 X's have that smog device on them like the California bikes have always had or not, does yours ? If so, you've got to either plug it with JB weld or install one of these, or you'll never get rid of the decel pop :
http://www.crfsonly.com/catalog/product ... ts_id/1044
With the smog thingie addressed , your JD kit installed per directions- it will have you open the fuel screw 1and 1/8th turns-and the airbox opened, you'll be ready to go with a bike that runs great. Once it's completely warmed up if you have decel popping just open the fuel screw counterclockwise an 8th a turn at a time until it ceases. Doug

[Smash]

I thought I read somewhere that the smog pump comes on all Xs now. Do you have a smog pump? If so get rid of it and that elminates it.

[BuckNrut]

I definately have the smog junk.

What is the best air filter to replace the stock filter?

Do most replace with a kit or just a new filter?

Thanks

[Zanardi4]

I definately have the smog junk.

What is the best air filter to replace the stock filter?

Do most replace with a kit or just a new filter?

Thanks

I got the Twin Air Powerflow Kit that includes the billet cage. However, the whole kit is not necessary. Many here just get the Twin Air flame resistant filter alone and just remove the now un-needed backfire screen from the stock cage. Be sure to get a Napalm filter screw while you're at it, you'll thank me!


.

[OLDFATGUY]

The new bikes here in ILL. have the pumps on them now. OFG

[[email protected]]

What Zanardi said plus DO get that smog bypass kit or plug the one on it with JBWeld, there's a great article on how to do that.
http://www.crfsonly.com/forum/viewtopic ... highlight=
Doug

[BuckNrut]

Well I just orderred

1 x CRF's Only Fuel Screw
1 x CRF450X'05-07 - JD Jetting Kit
1 x CRF450X'04-07 - Twin Air Pre-Oiled PowerFlow Filter
1 x Air Filter Mounting Bolt - Napalm Racing
1 x CRF450X'05-07 - Applied Racing Emissions Block Off Kit


Now all I need is a needle holder from a R or a 05-06 X? I think?

[whoya]

I got my needle out with needle nose pliers, no problems...

[crfsonly]

just a note to all '07 owners...the needle and retaining screw has been redesigned for '07. the idea is to make the whole assembly, needle and retaining screw, to be removed as a unit. as a result the needle will look different than the one you find in the jd jetting kit. never fear, it is compatible. instead of putting the needle through the retaining screw you put it in the carb first and then the use the retaining screw to hold it in place.

ken

[BuckNrut]

Ken,

does that mean I don't need the needle holder? Or I have the option of using a needle holder/letting the retaining screw from the jd kit hold it in place?

Thanks

[Zanardi4]

Just use the one that's already in your carb. It works just fine. That's what I used in my wife's 2007 TRX 450R quad, as instructed by James Dean when I emailed him with that same concern. Worry not.


.

[crfsonly]

Ken,

does that mean I don't need the needle holder? Or I have the option of using a needle holder/letting the retaining screw from the jd kit hold it in place?

Thanks

not sure what you are calling the needle holder...i have a feeling that it what i'm calling the retaining screw.

here's a picture that hopefully will help:



in the '07 design the needle drops down through the retaining screw and then the clip is put on the needle. the top "nail head" of the '07 needle keeps the fuel screw from passing through the retaining screw and the clip keeps it from being pulled up through the retaining screw. to use a pre'07 needle just put the needle in the carb and then screw the retaining screw into the carb to hold the needle in place.

hope this helps.

ken

[[email protected]]

Kens right, I see what he's talking about .
The 07 X needle 'holder' is different from the way it was in the 05 and 06 450X. I'd read in the Nov 2006 Dirt Bike that the needle holder (screw top)on the 07X didn't allow clip changes because there was only one clip space on the needle to begin with and that the needle was secured to the now hex shaped screw top.
So, I guess you CAN use that screw top after all, that's good news.

That's what I used in my wife's 2007 TRX 450R quad

I'll bet that's fun to ride Zanardi ! So, the TRX had the same evil one clip needle,huh ?
If I were to have a quad that'd be the one,that's a whole lot of quad right there. Doug