How to Access the Needle Jet 06-09 YZ450F

Looking for tips/tricks or the best way you've found to easily access the needle jet in the carburetor on an 06-09 YZ450F (mine's an 07 specifically). I'm trying to get my jetting spot on and i'm looking to richen up the needle a bit, or possible swap it out for a richer taper. I took the tank off the other day and it looks like an extreme pain in the rear to get to that needle. Thanks in advance! :smirk:

I tried the search funtion, but couldn't find any concrete evidence :rant:

Take the engine head stays off, loosen carb at airbox and manifold clamps, disconnect TPS and rotate carb. It's tight but doable.

John

thanks john, damn you're all over the webs aren't ya! lol

I was hoping there was some magical way of doing it without removing that uper mount. oh well!

If you have the spacial Yamaha tool it also makes the job easier. When you buy a YZF new it comes with a slick needle removal tool in the tool kit. It's a thin wire about 5" long that has a small rubber tube pressed on the end. The rubber tube grabs the end of the needle and pulls it out of the carb.

yeah, i've got that fancy tool with my bike. just need to get the top plate of the carb off first.

i forgot to mention that i'm also incredibly lazy LOL

Did mine without removing the head stays with no problem. Use the allens with the ball ends on them. I forget what they're called. They let you get at the cap bolts at a slight angle.

There's no easy way to do it. For me it's about not having to disconnect the throttle or hot start cables or crimping them in the process.

That means removing the subframe and the shock, then you can get the carb pulled back enough to do it. Definitely a PITA. Something you only want to have to do once.

I went with an NFLQ needle on my '09. My understanding is the '07 needle does not need to be changed since that year didn't have the "ice cream cone" muffler.

If you pull the head stays off...might as well check your valve clearance...

Did mine without removing the head stays with no problem. Use the allens with the ball ends on them. I forget what they're called. They let you get at the cap bolts at a slight angle.

now that's good info! I know exactly what you're talking about, we use them on aircraft all the time.

Use the allens with the ball ends on them. I forget what they're called.

They are called ball end hex wrenches :smirk:

I got some ball-end hex wrenches, and used that little wet-noodle-needle-removal tool that came with the bike. what looked like a serious PITA job turned out to be about 15 minutes! i only had to rotate the carb a couple degrees to get the rear-most hex screw out of the cap. thanks for the help guys!

Took the bike out for a quick spin in the desert, and it freaking RIIIIPPS, still might be a little lean though, it was kind of popping on decel.

168 main, stock needle - position 5, 45 pilot, 2 turns fuel screw. depending on how it rides this weekend i might try the .5 richer needle in the same position, but she feels damn good right now.

k&n filter and fmf/gytr can

"Kind of" popping on decel is what you want, but in any case, it's the pilot that controls that, so you might try coming out a quarter on the fuel screw. Consider the temperature where you ride, also, as low temps and altitudes add up to a leaning influence that will go away when the weather warms up.

i was also thinking about that. I live in the mojave desert, about 2300ft ASL, it's freakin cold right now, below freezing at night, and 50's in the day. but it'll be 100+ in 2-3 months.

I'll mess with the fuel screw, i did have a 48 pilot in it, and it did run well, but it was extremely hard to hot-start if i tipped or stalled. i don't think they make anything between 45/48 pilot jets do they?

thanks again for the help gentlemen!

i don't think they make anything between 45/48 pilot jets do they?

Nope.

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