So difficult...

Is it always so difficult to get access to the carb on a YZ450 08?

I decided to do an adjustment on the needle yesterday and it took me almost 40min to unscrew the two allen bolts on the carb...The frame makes the access almost impossible. Is there a trick to get easier access? or i did something wrong?

I found with all the aluminum frame 4 stroke bikes, the only real way to gain proper access to the carb is to remove the rear fender, side plates, air box, sub frame and shock.

You can try twisting the carb after loosening the clamps and going in on an upward angle, but on most it's almost impossible to get more than a few degrees out of it.

Lastly - you can try one of those ratchet type low profile screw bit drivers, but you tend to get a crappy bite on the screws....


i just unbolt the rear half, the sub frame ect... gets it done quick :worthy:

If all you want is the needle, remove the upper motor mounts. Takes a lot less than 40 minutes.

x2 on the motor mounts.

I had the same questions - I just picked up a '06 YZ450F - first bike in 10 years. It runs great but I was playing around with it last night trying to figure out how to service and work on it and quickly discovered that access is severly limited on this bike compared to what I used to ride, example..carb and spark plug. I guess once I get used to taking tanks and motor mounts and numerous other parts off when I want to work on it then it won't be a big deal. At least from what I hear the bike doesn't require a lot of service.

A long allen wrench works fine on the carb for adjusting the needle. I don't even bother to pull the motor mount.

I did recently discover though that taking the shock out is a much easier way to deal with re-installing the subframe/airbooth though.

The shock need not be removed. If you separate the air box from the sub frame (4 small bolts) You can then easily clamp the boot onto the carb. Following that, simply slide the sub frame over the air box and bolt it up.

I did that when i had carb off its the easiest way and i never had my shock out or my mounts off.

To adjust the needle you only need to remove the seat and tank. The allen bolts are easy if you use a long allen wrench that has the little ball end on them (Rocky Mountain M/C sells a nice set of Tusk wrenches for cheap). I had to change my needle at Mammoth a couple of weeks ago and it took me 10min tops from start to finish.

I have found that getting the air boot on the carb is a snap if you put the boot on 1st when attaching the subframe. Forget about the subframe bolts or lining them up until you get the boot on. I also use my finger to apply and thin coat of lube to the inside of the air boot lip. That makes the boot slide onto the carb much easier.


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