O.K. Here it is . i bought my yz about 2 months ago and the throttle has stuck wide open on me twice. The second time was at a local track about 10 feet before the face of a jump. I was in 3rd gear and well as you can imagine it wasn't good. I did everything in my power to keep the front end down in the air but the bike just natuaraly wanted to wheelie even with the clutch pulled in and the rear brake on. I landed in the flat about 10 feet further than i should have been. I landed flat on my back. luckinly the bike didn't land on top of me... Well, i broke my pelvis in 3 places and my sacrum was broken in half. This post is not intended to be about me or my injuries, I am wondering if anyone else has had a problem like this. I know the 01 was recalled for this very reason. I am concerned that maybe the problem wasn't fixed on the 02's or if the fix actually fixed the problem. Thanks in advance....
2002 YZ250 throttle Problems
- Thread starter intmach
- Start date
There has been a lot of skepticism on YZ throttles in the last few years, but some members refuse to believe it's a design flaw or something. There is definately something wrong with Yamaha's throttle or this would not be happening. How many times do you hear of a Suzuki or Kawasaki throttle sticking? Almost never! Yamaha issued a recall on throttles last year, but still a few DRN members, some of which are Yamaha dealers, deny seeing anything of this nature. I still think Yamaha needs to look at its throttle and redesign it, because this has happened on lots of bikes! You should definately call Yamaha and tell them to cover medical bills, bike repairs, and or any other inconveniences that you suffered from their throttle that doesn't work! What else happened to your bike? Anything?
- Aug 24, 2000
- 3,300
- 1
Yes, there was a recall, it is the roller in the twist throttle housing. I actually got the notice in the mail before my dealer knew anything about it, but as soon as they got their notice, I had my replacement part, free of charge.
- Thread starter
- #6
I owned alot of mx bikes in my lifetime and i never once had a throttle stick due to the pulley wheel it always happened because a slide problem or the spring on the slide. Yamaha setup my bike when i bought it from the dealer. Ya i made some adjustments to the brake lever and clutch lever positions. The throttle does seem to have some play in it but it is no more than my 96 suzuki rm250. It seems to me there is more to this than just an easy adjustment. Why was there a recall on the 01 if thats all the problem was? Why does the thing stick even if the cable is loose. This is a liability factor that i would not want to face. Don't you think it would be in there (Yamaha) best interest to fix the problem by makeing the pully wheel groove deeper or something. This seems to me to be something that could be fixed easialy........
- Aug 24, 2000
- 3,300
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The problem ran all the way back to the '96 YZ's I believe. The new part has a larger diameter lip on the pulley, eliminating the possibility of the cable geting pinched between the lip and the housing. It came about becasue of a few incidents like yours. For the most part, people were just blowing it off as a one time happening. The fix takes about a minute, and current models are equipped with the larger rim diameter pulleys. (At least they are supposed to be).
You may want to open up your throttle pulley housing and check that pulley to determine if that is what happened to your bike or not. There will likely be a mark on the rim of the pulley if the cable got pinched. If not, then there may be another problem elsewhere. This is just the most common stuck throttle problem with the YZ's.
Heal up fast.
You may want to open up your throttle pulley housing and check that pulley to determine if that is what happened to your bike or not. There will likely be a mark on the rim of the pulley if the cable got pinched. If not, then there may be another problem elsewhere. This is just the most common stuck throttle problem with the YZ's.
Heal up fast.
Intmach, I am very sorry to hear about your accident and injuries. There was a recall related to the throttle assembly for '01 models and prior. I believe that the problem has been fixed on the '02. I have had my '02 since September '01 and have not had any problems at all. I ride at least twice a week. I do keep up on my maintenance. Also, I have not heard of any other '02 Yz-250's having throttle problems in my area. I agree with the other posts that this was a major concern with prior model YZ's. If I am not mistaken a stuck throttle on a YZ ended Jeff Emig's career. However, I am sure they have fixed this flaw. Good luck in your recovery and I hope you are back riding asap.
- Thread starter
- #9
I will be disassembling my throttle assembly tonight to look for any defects I hope this is a isolated case on a 2002. This is to dangerous to ride until i find out what the problem is. By the way 2 weeks after the injury i am starting to ride my banshee and hopefully i will be back on my bike soon. Yamaha makes a great bike, it is to bad that this has occurred because i will never forget the helplessness i felt while the bike accerated up the face of that jump............. Rideon ........................
- Thread starter
- #11
RoosteR13, I took the throttle aprt and sure enough there are 2 seperate marks on the ootside diameter of the pulley. You can clearly see what happened here.
Does any one have a new pully Replacement for the previous years? If you could look at it and give me the numbers that are molded on the top of it i would apprecheiate it.... I'm calling Yamaha Monday.....
Does any one have a new pully Replacement for the previous years? If you could look at it and give me the numbers that are molded on the top of it i would apprecheiate it.... I'm calling Yamaha Monday.....
Nevada Sixx
Member
- Jan 14, 2000
- 1,033
- 0
yea, i'd call yamaha and tell them,, maybe they will make it even better for 03. And maybe you'll get something out of it, who knows.. sometimes, ive had my throttle stickdue to idle screw turned in too far, and it was touching my slide.
Well, what a timely thread. Yesterday (6/17) I was racing at Washougal,on an '02 YZ250, and going up the uphill on the 1st lap, my throttle stuck wide open!! Thank God I was able to scrub off enough speed before I went flying over the top into the valley. Well, I did go flying off actually, but I was able to save it. If the sticking would have happened another 20 feet up the hill, I wouldn't be writing this now. And for those who've never seen the upphill, its about 200 yards long, and your taped in 4th or 5th gear.
Now I did do some jetting earlier, so I assumed it was my fault, so I took it apart and I thought I found the answer, in that it seemed that the cable wasn't seated all of the way into its groove in the slide. So I tried it, but it stuck wide again. Thankfully I was prepared this time, and it didn't happen going up the hill. And after I stopped, I could feel a definate "kink" in the system, that then freed itself up after I twisted it a couple of times.
Anyway, we tore everything apart, including the throttle housing, and couldn't find a thing. NOTHING. But obviously there IS something. We couldn't get it to duplicate the "kink"
Hopefully we can find an answer here. SOON!!
Now I did do some jetting earlier, so I assumed it was my fault, so I took it apart and I thought I found the answer, in that it seemed that the cable wasn't seated all of the way into its groove in the slide. So I tried it, but it stuck wide again. Thankfully I was prepared this time, and it didn't happen going up the hill. And after I stopped, I could feel a definate "kink" in the system, that then freed itself up after I twisted it a couple of times.
Anyway, we tore everything apart, including the throttle housing, and couldn't find a thing. NOTHING. But obviously there IS something. We couldn't get it to duplicate the "kink"
Hopefully we can find an answer here. SOON!!
- Thread starter
- #15
Honda 65 thanks i was starting to think i was crazy.... I'm sure there are still sceptics out there though... Glad to see you were o.k. Check the Outside diameter of the pully in the throttle assembly for a small scuff mark caused by the cable pinching between the pulley and the throttle assembly housing.
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- Aug 24, 2000
- 3,300
- 1
I hope you both get the problem taken care of, being stuck WOT is scary, dangerous and sometimes even worse.
Keep us posted on what you find on yours HONDA65. It sounded like the pulley problem again, but if you found no damage or marks on the pulley, perhaps it is something else.
Keep us posted on what you find on yours HONDA65. It sounded like the pulley problem again, but if you found no damage or marks on the pulley, perhaps it is something else.
Even though I checked the pulley wheel, I didn't check the outer edges for scuffing. I did notice that it doesn't spin in the housing, but that the cable just slides through the groove. But even with that, it didn't seem like it would bind up the way it did. I can't help but wonder if the wheel on the throttle sensor that rides on the slide gets bound up inside, kind of between the slide and the carb wall. But I didn't see any scoring (will look closer today).
On a possible side note, I called Carb Parts Warehouse to see if anyone ever swaps out the TPS carb for a standard PWK and they said the sell about 2 a week. But he said no one had mentioned that they wanted them because of our problem. But I can't help but wonder.....
On a possible side note, I called Carb Parts Warehouse to see if anyone ever swaps out the TPS carb for a standard PWK and they said the sell about 2 a week. But he said no one had mentioned that they wanted them because of our problem. But I can't help but wonder.....
Of course he could've been exagerating the numbers.
Anyway, I tore everything apart, and still nada. No scoring, nor rough edges, nothing. No dirt, sand or grunge. Oh, and the wheel DOES turn OK. My mistake on that one.
To be honest, I can't remember if when I noticed the "kink" and freeplay, if the bike was still running or not. My mind was racing alittle as one might imagine. So if it was still running, could it be some sort of vapor lock, due to a high velocity of fuel and/or weak spring? Isn't that why they put push/pull cables on 4 strokes? I'm pretty sure that happened to me back in 94, when I put a Kehien on my '94 YZ250, and I had cut the spring. It locked full throttle, again at Washougal, and I flipped right off the back. I was sure it was mechanical, but could find nothing. And then someone told me not to ever cut the spring, just for that reason. MAybe the newer YZ's have a lighter spring, and needs to be stiffer.
Well, hopefully some one will have a fix, before one of us gets killed!!
Anyway, I tore everything apart, and still nada. No scoring, nor rough edges, nothing. No dirt, sand or grunge. Oh, and the wheel DOES turn OK. My mistake on that one.
To be honest, I can't remember if when I noticed the "kink" and freeplay, if the bike was still running or not. My mind was racing alittle as one might imagine. So if it was still running, could it be some sort of vapor lock, due to a high velocity of fuel and/or weak spring? Isn't that why they put push/pull cables on 4 strokes? I'm pretty sure that happened to me back in 94, when I put a Kehien on my '94 YZ250, and I had cut the spring. It locked full throttle, again at Washougal, and I flipped right off the back. I was sure it was mechanical, but could find nothing. And then someone told me not to ever cut the spring, just for that reason. MAybe the newer YZ's have a lighter spring, and needs to be stiffer.
Well, hopefully some one will have a fix, before one of us gets killed!!
Oh and Buzz Bomb, about Suzuki's and KAwasaki's not have sticking problems, I'm not sure I agree. Remember that since 99, KX 250's have been running the TPS's and RM250's have been since '01. I remember several KX's having throttle sticking problems, though I don't recall what was the diagnosed problem. And I had a '02 RM250 that the throttle also would stick ,but seemingly on at lower throttle openings, like it had a high idle. I replaced the cable and carb top, and it seemed to cure the problem. However, I only rode the bike briefly after that, so I'm not sure if the problem was truly fixed.
AND, all three bikes share an almost exact throttle housing assembly. So personally, I think its in the carb itself. But what it could be is beyond me.
AND, all three bikes share an almost exact throttle housing assembly. So personally, I think its in the carb itself. But what it could be is beyond me.
WAY back in 86', the CR250's were having problems with throttles sticking...ended up being the filter rubbed the subframe rails hard enough when removing that sand/dirt particles were falling into the airboot. The fix was to lay the bike on it's left side when removing the filter, because of the bend in the boot dirt/sand could not fall in then. Remember guys, all it takes is 1 grain of sand/dirt sucked into the tight tolerance's of that slide to stick the throttle.....SCARY stuff.
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