'05 WR 450F Throttle stop

Just bought a new 450F, and im dying to see what kind of power is available to me. I have already made a couple mods, but i have heard so much about this throttle stop. Can anyone describe to me where it is and give me a step by step process of how to do it? Any kind of help would be great.

It's on the right side of the carb underneath where the throttle cables go. Look in your manual and you'll see exactly where I mean. All you need to remove/replace it is a 4 or 5mm hex head (Allen) wrench. Replace it with a YZ stop and you'll be good to go...SC

Of all the free mods, shortening the throttle stop screw produced the most dramatic result. On the '05 you must peel the AIS out of the way to get a good shot at the screw. Mine was *really* glued in with loctite so it took some patience to remove it.

Will you need to go through a dealer to find the YZF throttle stop, or is there an after market place that will have it. Any suggestions?

Buying the YZ Throttle stop screw is the easiest way.....only if you're going to the dealer anyway; but it is free if you just shorten the stock one to 18.23mm. That's 18.23mm shank length excluding the screw head.

Is this screw outside or inside the carb? The diagram on the Yamaha parts pages are really tough to understand. Do I need to pull the carb, loosen it so it can be turned, or just do it in place?

You can do it without moving the carb. :naughty:

Take off the AIS (Air Induction system) 2 screws that are on the frame facing rearward and let it hang. You might want to take off one of the hoses that leads to the other side of the bike and into the airbox to make your life easier.

Behind where the AIS was, remove the plate that covers the throttle linkage. Not sure if I'm using the right vernacular here. The plate is held on by two allen screws. Once the plate is off you will see the screw. The head in on the bottom and it is pointing up at about 1:00. It is help on with locktite so you will have to strong arm it just a bit to get it moving.

Just get the YZ screw and replace, for the money I think it makes a cleaner job but if you are good with a saw and ruler you can cut the old screw. Also get a little locktite (medium) and put a drop on the threads of the replacement screw. button her up and you are good to go. Don't forget any hoses you took off the AIS. The link in one of the responses above has the Yamaha part number to make it easier to order.

Excellent instructions! It took me a minute to locate the screw. I expected it to be inside the area covered by the plate you described. Not! It's on the back of the carb and you might be able to get to it without removing that plate, but it would be much harder. Now it's off to Yamaha to get a YZ piece. Looks like the YZ piece must be about 1/2" (12.77mm) shorter, correct?

Thanks again! I appreciate it. Now maybe my WR450 will feel more powerful than my old IT490. I have been a little disappointed so far, but I realize I'm not getting anywhere near full power from this bike with this old screw in place.

Too bad we will be getting 4" to 8" of snow tonight. :naughty:

Wow! That's definitely more power than my old 490! Best $13.00 I ever spent.

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