Jump to content
Sign in to follow this  

WR250f throttle stop mod.....

Recommended Posts

Hello fellow thumpers. I am relatively new to dirtbiking. I've ridden when I was a lot younger and now I'm slowly getting back into it. I recently upgraded to a WR250f and deciding what mods I want to do to it. I did the grey wire mod already. Now deciding if I want to do the throttle stop mod or not. I'm not all that technical so can some one explain to me what the throttle stop mod does in "lay" terms. From what i've read the throttle stop is set to 3/4 only but doing this mod opens it up fully. Now forgive me for my lack of understanding, does this mean that when you turn your actual throttle, with out the mod, it only makes a 3/4 turn thus reducing approximately 1/4 of untapped power (because you can't literally turn your throttle more) or does it mean that the air from the throttle screw is restricted to only 3/4 capacity.

Bottom line is this, does this mod increase top speed or torque or both at low end or high end? Thanks.

Share this post


Link to post
Share on other sites

I believe it limits the range of the throttle slide. It does make quite a difference.

Also you should do the grey wire mod which doesn't restrict timing in the lower gears. Also if you have an off idle bog, you may need to change your leak jet and do the o-ring mod.

There are lots of threads on all of these things. It makes the wr almost like the yz with wide ratio tranny!

Share this post


Link to post
Share on other sites

With the WR throttle stop screw your throttle is limited to 2/3 opening, period.

The twist throttle won't turn past that much because the screw stops it (in the carburator).

The mod definately increases top speed and torque at high end RPMS....

I felt it was the best mod one could do to the bike.

Share this post


Link to post
Share on other sites

thanks. That is the answer I was looking for. I've cut the grey wire already. Your answer I think has convinced me to change the throttle stop. Do I need to adjust anything on my bike after this mod? Thanks.

Share this post


Link to post
Share on other sites

what year is your wr i have one thats for an 07 are newer wr that came with the ais removel kit the i did not use if you want it pm i will mail it to you. i also have the new needle that comes will the kit you can have with it are anyone else that wants it

Share this post


Link to post
Share on other sites

Thanks. But my WR is an 05 model. I bought it from a friend who bought it brand new in 06 and had put only 130 miles on it (he mainly rides quads). But the bike was in pristine condition and so far I have been very happy with the bike. I used to ride Honda in the past and this is my first Yamaha. So far I'm loving the WR. I think I'm going to do the throttle mod as soon as I get a chance.

Share this post


Link to post
Share on other sites
why do they limit the power on these bikes so much anyways

To get past the emission standards.

Share this post


Link to post
Share on other sites

Ok. I opened up the throttle stop box and found out that instead of the standard allan screw that is supposed to be there, there is a phillips screw instead. I didn't take the screw out cuz I didn't want to mess with the unknown. Is there a way to determine if this mod has already been done? If the mod is done should the throttle tube be able to rotate a full complete turn? And for those who question if it was the screw, it was. I used other links with pictures to make sure that is the screw in question.

Share this post


Link to post
Share on other sites

I think it is supposed to turn about 3/4 turn with the YZ screw in there, I'd have to go check on my bike.

The easiest way to find out if you're getting your full throttle play is to take out that screw you identified, measure it, and compare it to values you find around this site.

Share this post


Link to post
Share on other sites

i thimk you are looking at the ac timing adjustment screw that is a phillip

Share this post


Link to post
Share on other sites

Much thanks to Landshark for sending me the stop screw. Fit perfectly. For some reason like I said before, there was a phillips screw in place of the regular allan screw stop. In any case, fit and worked like a charm. Once again big thanks to Landshark for sending me the screw. Took it out for a quick spin and loving the power.

Share this post


Link to post
Share on other sites
Much thanks to Landshark for sending me the stop screw. Fit perfectly. For some reason like I said before, there was a phillips screw in place of the regular allan screw stop. In any case, fit and worked like a charm. Once again big thanks to Landshark for sending me the screw. Took it out for a quick spin and loving the power.

Very cool of you Landshark. You sent me a hot start for my bike for just the shipping and I thought that was really cool. Looks like you've done it again.

VERY cool. Thanks!👍:thumbsup:🤣

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...