03 throttle stop

How much should be cut off throttle stop? One post read said 11 mm to be removed. I would like a few replies before making the mod.

Try putting a nut on the screw for a spacer. The slide should just pass the top of the throat when the stop hits. sneek up on it. Best choice is to buy the YZ stop. The dealer I bought mine from cut it way too short. I have ordered the YZ stop but has not arrived yet.

I can comfirm that the yz450f throttle stop is 11mm smaller than the wr450f. I measured both. The yz is 23mm wr is 34mm

i pulled the carb, trimmed a little at a time until slide was almost all the way open. I do believe that it can be trimmed to short. May cause problems with ECM and TPS. I was very surprised that a stock WR screw only allowed throttle to open HALF way.

Did you look at the slide. If so where did it stop? When I checked the stop the dealer cut, It Never touched the pully? :) I think he just did not care and only used the screw to plug the hole! :D

11mm? Uh, I cut the whole damn post off :). Was that a bad idea? The slide opens all the way now.


when i looked in the throat of the carb (part that air box clamps to), i have the slide stop about an 1/8 of an inch from the top of the throat. i repeat my slide does not go all the way up. this type of carb is new to me and i did not want to cut off to much. i think there are two different measurements on TT, one says 7 mm and the other says 11 mm I THINK. I chose to use these numbers as a gauge ONLY. I do not think the last 1/8 inch of slide will slow me down that much. But if it does i can always trimm it a little bit more Right ???.

number82, i think cutting the whole thing off is bad. there are two issues going around. first - if the slide goes to far, it may send wrong data to the ECM. Second there may be some damage to the slide, over time. Once again this is my first WR and my first experience with this type of carb. But i have been riding and working on bike for a while.

If you cut the whole post off, It open past all the way! :) Now your in the same shape I'm in. :D I think the TPS will give false readings if you go too far with the slide. I have seen that posted in the past. If it would quite snowing or raining here I would go to a track and test it, but at this time it is only a theory to me.

I think you have done the smart thing. I'm not sure either if the 1/8" from top will make a difference, but I'm sure your on the safe side. :)

yep i know what you mean. 28 inches of snow Sunday and Monday ( Baltimore, MD. ). I'm just about ready to go rippin down the street.

I bought the YZ stop and measured it against the WR stop. The YZ stop is 11mm shorter. Just cut 11mm off of stock and reinstall it.


What I did is unscrew the throttle stop and put it in the hole with the throttle held wide open. Then marked it and measured it to the collar of the screw. Then took that measurment from the end of the screw, added 1/8 " (just to be sure it gets WFO :)) and cut it there.

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