Throttle-stop part #?

Hi all. This is my first post to this group having sold my KLX300 on Monday and buying a WR400 the next day. By the way, the WR is twice the bike the KLX is. I took the WR for a ride at Pozo yesterday and could not believe the power difference between the two. Anyway, could someone please supply me with the part number for a 99 yz400 throttle restrictor? When I checked to see if the previous owner had trimmed it, I found out he had removed it. From reading the information on this forum, I believe it needs to be re-installed and the yz400 model will work best. Thanks.

You CANNOT purchase the throttle stop for the 99/98 WR's.

You have to buy the ENTIRE carb body ~ $800.00.

I know, I have tried!

I have a part number I think might work for the bikes in those years. I know it was for the yz a few years old and it worked great without trimming in my 2002 wr 426. It is 5JG-14591-00. GOOD LUCK, Mark

This may have been covered in the past but why is it better to be chopped than removed?


Originally posted by MOmilkman:

This may have been covered in the past but why is it better to be chopped than removed?


One reason I've heard that makes some sense is that w/out the stop you may damage the TPS or at least move it out of adjustment.

I saw a post where the guy claimed without a stop screw it over rotated the throttle shaft and caused a backfire as I recall. He said he put in a stop screw and it fixed it. I noticed when I put in the YZ screw I mentioned above in another post it wouldn't allow the throttle shaft to rotate quite as far as it would without the screw installed at all.(But, still a whole bunch more than with the stock USA model screw). So mine ran great with the YZ screw and saved me from cutting it off and not knowing which of the 56 different lengths to use and exactly how it was measured etc. Hope this helps. Mark

I found the part number again. It is 5JG-14591-00

The correct answer is that without some kind of throttle stop installed the slide will bang against the top lid and damage both the slide and the lid.

You can also get a 3mm threaded screw from the hardware store and insert it from the bottom to the top. Adjust the screw out until the bottom of the slide is opened to the top of the opening. Install a locking nut and adjustable locking throttle stop screw. It works great, I've done it on two other 99's without stops installed. Some dealers were just plain stupid back then and removed and tossed them....Lucky I got mine out of the crate.

Bonzai :)

Somebody want to tell me where its at in this picture?

I guess I need to get mine back in. When I bought my bike new my dealer took it out and handed it to me. So I still have it. (luckily)

How much do I need to grind off of it?


I looked at this picture when I first bought my bike and the parts guy and I couldn't find it either. Then I saw a post on TT with the number and we still couldn't find it. So Thank You TT. What year is the diagram for? I think that will be your answer if it isn't for a 99 yz.

Well, my bike is a 99 WR and thats the right fische for my bike.

You will not find it on this fiche. You CANNOT purchase this part for the 98/99.

At the dealer, I looked on the 2K fiche and found it. Then we put the 99 back in to locate. We looked in a book and found the picture for it, but NOT the part #.

Dealer told me, "Not Avaialble". I called Sudco (Carb Parts Warehouse?). The guy knew of the problem, but did not have the part available. :)

Originally posted by NH Kevin:

You will not find it on this fiche. You CANNOT purchase this part for the 98/99.


I dont need the throttle stop. I already have it. I just need someone to point out to me in the diagram whereabouts its supposed to go so I can chop it (how much?) to the specified length and put it back in.



Makes me glad I have a Canadian model

All too wierd - I just walked into my Yamaha dealer, gave him the part number, he ordered it, a week and about 12 bucks later I walked out with it. We never could find a fiche for it. Maybe we just didn't know enough, as all we did was blindly order the part number.

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