missing throttle stop screw

after reading through several post I noticed that most of you guys have shorten the throttle stop screw or replaced it with one from a yzf. I had the dealer do yz timing while doing some other work and they removed the throttle stop screw. I have heard that without the screw the bike will run poorly at wot, I have not noticed it but, I have not ridden with one in place. Do I need a throttle stop screw????

You will prob get a few different opinions on this, but heres mine:

Mine was taken out when I bought my bike. They saved it for me, and after breaking it in, going full throttle DID affect WOT. I shortened it to 23 mm, put it back in, and the WOT cleared up. My advice is put it back in, shortened, and then forget about it. If you need one, I ordered the YZ, got the WR's, and have it sitting in a bag. Only cost me $13 to put it in a plastic bag!

PS-I wanted the YZ length, thats why I ordered one before cutting down the WR stop. I got conflicting advice as to the length, but after confirming it, I wasnt about to spend another $13. If you want mine let me know.


Thanks for the advice, I will be going to yamaha today to order some jets and I will add a throttle stop screw to my list.

Thanks again


Good luck ordering one, the PN is not on the micro fish. I have a PN for the YZ stop at home, I ordered it and it is not the right screw. I have to look a the numbers and see if they are the same. I still dont have one now,,,,,,,, :) . And yes, I notice the bog out at WOT.

Ditto Jason-

I ordered the YZ stop, and some how ended up w/ the long WR screw.


If you come up with the number please let me know. thanks, jay

YZ PN 5JG-14591-00-00 took two seconds of using the search mode. :)

Thanks Rick, should have thought of that myself.


Yeah, that looks like the number I had. I got it from this site. I will try to remeber to check it tonginght, anyway, what I got when I ordered it was not even the right thread size to screw into the hole :) .

Ok, I got the number, I ended up with a 5JG-14591-00, and ITS NOT THE RIGHT PART!!!! I dont know if the extra 00 means its a diffrent part or what, but this one like I said is way to big to even fit into the hole.,,,,, hmmmmmmmm. anyway I am still running without one, I just dont go WOT or when I hit it I back off if Im in 5th or up shift If I am in any other gear.

the throttle stop stops the slide about 1-2mm from the top of the housing. in other words if you pull the throttle stop out the slide will carry on for 1 more, that's ONE more millimetre ok?

you've been on full throttle and main jet for ages when this happens so there is no way your jetting is affected in anyway whatsoever. none. no chance at all.

so that leaves the TPS.

are you telling me that after 43mm of lift the TPS goes nuts on the 44th millimetre!

if somebody has pulled out their THROTTLE STOP and it doesn't run right then it's their jetting that isn't right and nothing to do "without" the throttle stop.

i run my bike without THE THROTTLE STOP so that i can imagine i've got hold of a few TT members and wring it's neck. i tend to try and ride flat out with a manic glare really wringing it's neck. i feel better after that.

some of you have got jetting all over the show, too lazy to sort it but it's easier to just blame the product, any product than say "i haven't sorted my bike"



[ December 20, 2001: Message edited by: Taffy ]

I'm running my 450 without a stop and it runs quite well at WOT.

Hej! Greetings from Sweden :)

I have no stop on my wr400 –98 and that’s the way it was when I got it. First I noticed the bike running like I’ve seen some explain in TT at wot. So I opened the instruction book and found out how the TPS should be adjusted. Sense I had on my TPS the resistance 4,1kOhm it should according to the book be, 4,1 multiplied with 0,13-0,15 (if my memory is right) that is, 533-615Ohm at closed throttle (idling). And then it should be within the spec 0-5 +-1kOhm which it is (I think) having following data in my case: 560Ohm idle and 4,2kOhm at wot. I tryed it out and woala no more “rpm restrictor”. Trying with a throttle stop screw (just found one in the garage that fitted) before I adjusted the TPS, did not in my case give any results… my TPS was at +800Ohm in idle position before I adjust it, giving to high Ohms at idle (I think). For me this means that if I was to put the screw back on I will have to high resistance at idle once again, that is I have problems to get the TPS up to and over 4kOhm with a restrictor screw on. Also I feel the bike tends to start more easily in the could (here is now –20C) but that cold just be imagination…

Q: Isn’t it just to adjust the TPS to right resistance and skip the screw (or use it to stop the plate from banging in to top at wot) that it’s all about???

This is my first writing in this excellent site. I thank you all for VERY useful tips!! Keep in mind, I’m no expert what so ever. Have been biking all my life (well almost) but just recently started with enduro.

Ps. If any of you follow the Dakar 2002 there is a Swede, PG Lundmark #16 http://www.pgdakar.com competing who is from the same region around the polar circle, as me. Hi is a great source of inspiration (his training camp for the desert race is in the snow :D for a beginner like me! I know, this is oftopic as...(hi´s not even on a Yamaha) just couldn´t resist to write it :D Ds.

[ December 20, 2001: Message edited by: Longstream ]

[ December 20, 2001: Message edited by: Longstream ]

[ December 20, 2001: Message edited by: Longstream ]

[ December 20, 2001: Message edited by: Longstream ]

what you mean wind people up? never!!!

fishings not my game :):D

i like boxing :D:D

bob and weave, bob and weave :D:D


:) Yes I figured......too much waiting for a bite ...fishing!

Boxing is much more your game! LOL :D

Well Taff, do I think 1mm on the slide is the problem,,,, NO!!!!, Do I think the ignition will flake out if the TPS goes off the range,,,, YES, Hey Taff, why dont you take your TPS OFF or just knock it loose and spinn it around a bit with your eyses closed, tighten it back up whereever, start your bike up and write back that you dont have YOUR jetting sorted out cause YOUR too LAZY,,,, :) .

The TPS is adjusted to a specfic range, It, like the jetting, on two identical bikes, can be diffrent, so its possible that one bike will run fine with out the stop cause that dose not throw its TPS off the range, but another bike without the screw is off the TPS depending on where it is adjusted, and needs to be for that bike to run right.

:D Taffy......Do you enjoy FISHING by any chance...ROFL

I just wondered! :):D

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