Air Box Mod Question

[strykmaster]

Originally posted by Woody_CRF
Both vents are removed, and the box has been shaved. Pretty easy when you heat the blade up with a torch

Yep....mine was too. I didn't even heat the blade. Yours must of gone through like butter.......sweet.

[Woody_393]

Yep, she did. She's done. I finished early this morning so I've not had a chance to ride it or even start it yet...

I went with a 175main, blue needle 3rd click from top, & 1.5 out on fuel screw. mmm... I still absolutely love that sme fuel screw. I'm not sure what I did before I had it.

[yz250fkid]

i wouldnt go through the same proccess for a yz250f would i?

[Roostman]

Cool Woody, Im gonna take mine off also. What part of the airbox are you cutting?

[Woody_393]

Ok, I just rode it, and it seems like it hauls booty... The blue needle is certainly different then the red one. The power for me felt a lot better down low, but not quite as good up top, not bad, just not quite as mean on the top.

I went out to where my bro and I were drag racing and did immaginary drags, and I was killing everyone..

No seriously, I used to hit 5th right before the finish line, now, I'm hitting it a good ways before the finish... And boy how does that front tire like to stay in the air... Now I just need to ride it back to back with bates bike. Oh, and I went to 1.25 turns out on the fuel screw and she sounds good.

Roostman, if you can wait until later (after I get some sleep), I'll post all the pictures I took along with the explanation. I made sure to take a lot of pics. It's really easy though...

[strykmaster]

Originally posted by Woody_CRF
Ok, I just rode it, and it seems like it hauls booty... The blue needle is certainly different then the red one. The power for me felt a lot better down low, but not quite as good up top, not bad, just not quite as mean on the top.

That's exactly what JD told me. Blue, better power off bottom. Red, better top end. I might end up sticking with the red for the wide open desert. I will be putting in my blue needle on Thursday and be trying it out on Friday just to feel the difference. Maybe I'll like it better?

[Woody_393]

All I know is that in corners, it would lift up the front tire while i was still leaned over if it didn't break the tire loose. it was also leaving a serious rut where I was taking off. Where as before it didn't, it hooked up better and didn't break the rear tire loose as bad.

As far as the air box mods... I couldn't tell a difference since I changed the jetting at the same time ... I shouldn't have messed with the jetting so I could tell. I just know she hauls *** now. I can't wait to ride it back to back with bates bike to see if it's just wishful thinking or if it really is faster. I'm sure it's faster though, it was actually a little scary fast. AND DANG I need some spoiler or something to help keep that front tire on the ground...

[Metal]

I just unscrewed my ducts from my side number plates. Why were they there in the first place, they seem so restrictive? Does anyone know any drawbacks to removing them? I guess I am just paranoid about removing factory items. Is the metal screen inside the air filter what everyone is refferring to as the "Backfire Screen". If so how safe is it to remove( I am using PJ-1 cleaner) . And my final question for you seasoned pros, How hard is it to install the different needles in that JD kit? Thanks all!

[Faded]

Metal,

On Shifting's we just removed the screws and the ducts on the side panels. The screen on his CRF also just pulled out, no cutting required. I would say that you're pretty safe running without it. Changing the needle requires a little time but is by no means brain surgery. Hope this helps.

Woody, you line up with Bates yet? Ryan and I did a few starts the other night...it was fun.

[bates393]

When removing the screen just make sure you are not cleaning your filter with gas. You could have a "hot seat" if you do. The needles are easy to change. Take your seat off, your gas tank and then just remove the top of the carb. Twist the throttle and it will lift the alan head up for easy access. Remove alan head and then remove and replace needle. Hint - you can leave your shrouds on your tank when you take them off. Saves you a bit of time. Only drawback of helping the bike breathe better is you will have to clean your filter more often(most likely).

Faded - Woody and I have not lined up yet

Bates

[Faded]

Originally posted by bates68_03CRF

Faded - Woody and I have not lined up yet

What's the hold up? :

[bates393]

Here is a pic of woodys moded airbox you can see how he trimmed the plastic down. Now when the side panels are on the airflow is not restricted. All you need is a razor knife and about 10 minutes to do this.

[bates393]

Originally posted by Faded
What's the hold up? :

Wish I had a good excuse other than we have not been riding for a couple weeks

[drman]

Hmm...if I am thinking right, couldn't alot of different bikes have this same mod done to it? My RM has the vents in the sidecovers, but they seem pointless to me with the airbox right behind them-not letting air go into it.

[Metal]

Thanks Gents for the advice

[Woody_393]

I don't know why not...

[drman]

Ok I did it-can't tell much of a difference at all, maybe a bit more bottom. Oh ya, I can hear it suck air through the vents now though... lol It also seemed to help my rich jetting.