CRF Needle

[blacknblue#2]

We have a stock needle for a CRF in the garage here that we took out of a friends bike. Another friend has an 06 450R wit a slip on exhaust, 180 main jet and a filter. It seems like it needs a little more fuel because it runs better with the air box lid on than it does with it off, and he asked me if that CRF needle was any different. I look up the parts schematics and they show a couple different part numbers for the needle but i dont know what one i got. Will a stock CRF be any different than his stock needle and would it help it at all if it is a little different???

[Nick110]

Yes the stock CRF is different. It is adjustable unlike the the stock TRX. It will help for your situation.

[d3ktrix]

So its an 06 450r with a 180MJ and it still runs better with the air box lid on...
Either its super cold by you, the bike has and air leak, or the pilots lean.
Thats a really big main jet for a mostly stock 06 engine. Should be rich no matter what.

When you say it runs better with the air box lid on, is the top end power better or low end?
Is is popping on acceleration or deceleration with the air box lid off?
When you put the lid on what changes?

And yeah the CRF needle will work, though it sounds like something else might be off too.

[blacknblue#2]

right now its around 37 degrees here, he said it has always ran the same since last spring when he done his mods. it just didnt have the throttle response it should have on low end. Wide open it ran good but it just seemed like it was starvin for something from idle to about mid throttle which i think makes since since it was gettin all this air with the factory fuel intake on the needle?? i told him to try it with the air box lid on so that it wouldnt be suckin so much air and it really did help it from idle speed and up. I forgot to add this bike has a quickshot on it too...................What clip should i run the CRF needle on with just these mods??

[d3ktrix]

What pilot and leak jet is he running?
Does it bog when u snap the throttle off idle?

Should be around a 45pilot.
And a #55 leak jet.

Both will help off idle throttle response.
That combo'd with the CRF needle should give it nice throttle response.

[Nick110]

4th clip from the bottom.

[eastside 400]

not all CRF carb needles are adjustable, both the needles in my CRF carbs are non adjustable, i think the 04 and up ones are but not sure