Throttle stuck WFO on a 2-stroke

Turbojez
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Turbojez
Like the title says, did you have any situations like this before?
I had it on a friend's 2004 YZ 125 which led to a crash, was wondering how often does that happen and if it happened to any of you guys?

Side note: It was stuck in the carb, not throttle tube/cable, as I remember rolling the throttle all the way back before the accident. Guess I just wasn't fast enough (or too much armpump slowed me down) to pull in the clutch.
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Starcrossed
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Starcrossed 12/29/2016 6:30am
12/29/2016 6:30am
When they get stuck, it's always WFO Laughing Hope you're OK. Keep those carbs clean. Wink
tempura
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tempura 12/29/2016 7:03am
12/29/2016 7:03am
Never had a throttle stuck on a dirtbike
smashingpumpkins167 12/29/2016 7:09am
12/29/2016 7:09am
I had mine stick after reassembly. I just had to Jimmy the throttle cable a little bit and it fixed it. I freaked out thinking it was a huge air leak.
yak651
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yak651 12/29/2016 7:34am
12/29/2016 7:34am
Yep, KTM150sx made me sell the bike and made me contemplate giving up riding/racing. Ended up with a collapsed lung, a bunch of broken ribs and major bruising on my thigh to the point I thought I broke my femur. Not a good experience. Google stuck throttle and you'll see some scary go pro vids of it happening to others.

Reason I sold the bike was because I could not find anything wrong with the slide, throttle cable, throttle housing etc. I did replace the stock cable with a Motion Pro because if you do a search this has happened to other KTM owners with more frequency than other brands it seems.

About two years ago was behind a guy on a KTM 250sx going up a table top and his throttle stuck also, he ended up with broken pelvis and also broken ribs...
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ROCKNDAWG
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ROCKNDAWG 12/29/2016 7:56am
12/29/2016 7:56am
yak651 wrote:
Yep, KTM150sx made me sell the bike and made me contemplate giving up riding/racing. Ended up with a collapsed lung, a bunch of broken ribs and...
Yep, KTM150sx made me sell the bike and made me contemplate giving up riding/racing. Ended up with a collapsed lung, a bunch of broken ribs and major bruising on my thigh to the point I thought I broke my femur. Not a good experience. Google stuck throttle and you'll see some scary go pro vids of it happening to others.

Reason I sold the bike was because I could not find anything wrong with the slide, throttle cable, throttle housing etc. I did replace the stock cable with a Motion Pro because if you do a search this has happened to other KTM owners with more frequency than other brands it seems.

About two years ago was behind a guy on a KTM 250sx going up a table top and his throttle stuck also, he ended up with broken pelvis and also broken ribs...
A friend of mine had the same thing happen, also almost on the same bike except it was a 125 KTM. And he broke almost the exact same things you did (except he broke his scapula also!) He no longers rides.
He always rides a 450, he probably should have stayed away from the 125.
se7enmx
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se7enmx 12/29/2016 8:17am
12/29/2016 8:17am
My Kawi 450. My life flashed before me.
LungButter
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LungButter 12/29/2016 8:44am
12/29/2016 8:44am
Yep. Scary shit.
Stuntman949
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Stuntman949 12/29/2016 8:49am
12/29/2016 8:49am
KX500. The replacement throttle tube had a slightly misshaped cam.
Sachmo831
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Sachmo831 12/29/2016 8:51am
12/29/2016 8:51am
I had a 99 kx250 that would have a hanging idle issue through stutter bumps. It happened only a handful of times. Definitely a scary feeling when you chop the throttle and it's still pulling!
bvm111
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bvm111 12/29/2016 9:03am
12/29/2016 9:03am
That's what the kill switch is for and the clutch, oh and cleaning the airfilter and making sure you tighten the clamp at the the air boot so it doesn't suck dirt, yes I know this is a run on sentence it's on purpose that what happens when I'm hungover Whistling
Robgvx
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Robgvx 12/29/2016 9:14am
12/29/2016 9:14am
Sachmo831 wrote:
I had a 99 kx250 that would have a hanging idle issue through stutter bumps. It happened only a handful of times. Definitely a scary feeling...
I had a 99 kx250 that would have a hanging idle issue through stutter bumps. It happened only a handful of times. Definitely a scary feeling when you chop the throttle and it's still pulling!
Had you, or a previous owner cut the throttle spring in the hopes of making the throttle lighter?
shuggs
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shuggs 12/29/2016 9:14am
12/29/2016 9:14am
Had it a couple of years ago on KTM200 going over a tabletop, sh$t my pants but before I knew it I had smacked the ground, ass first, plastics on bike were destroyed, bars bent, sub frame snapped on one side.

Took throttle to bits and cable had fraid so it was all my fault for poor maintenance!!!

Took ages to recover from pain in tail bone, wouldn't be surprised if I broke something but im a daft old fekker so just got on with it.
wide open wally 12/29/2016 9:15am
12/29/2016 9:15am Edited Date/Time 12/29/2016 9:17am
bvm111 wrote:
That's what the kill switch is for and the clutch, oh and cleaning the airfilter and making sure you tighten the clamp at the the air...
That's what the kill switch is for and the clutch, oh and cleaning the airfilter and making sure you tighten the clamp at the the air boot so it doesn't suck dirt, yes I know this is a run on sentence it's on purpose that what happens when I'm hungover Whistling
Sometimes that doesn't cut it lol. Racing my dads '83 CR 480 and hit a turn and felt it pull way more than I was wanting so I pulled the clutch in and the kill switch wouldn't cut it. Said screw it thinking my kill switch was bad, reached down and tugged the spark plug cap off knowing I was gonna get lit up lol. Still didn't work. Shifted to 5th found a tree then planted the front wheel and dumped the clutch. Managed to kill it. All the old timers filled me in, if a bike has any carbon build up and the throttle sticks wide open, the carbon can heat up and glow, rendering no need for a spark plug (kill switch won't work). Rare but it happens lol
Tracktor
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Tracktor 12/29/2016 9:35am
12/29/2016 9:35am
Wasn't there a recall/lawsuit due to carb plating or some such on YZ125's? Some dude got paralyzed if I remember?.......
AzTrooper
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AzTrooper 12/29/2016 9:35am
12/29/2016 9:35am Edited Date/Time 12/29/2016 9:55am
While I was riding at the local track in 2002, the throttle stuck on my 1980 CR250R on the face of a jump. Thats when I broke my back. What caused it to stick open is that the locating pin used to keep the slide from rotating on '78 - '80 CR 250's in the carb bore is made of a plastic of some type and looks to be cast or molded into the carb body. Best I can tell is that the locating pin had become worn and broke off and jammed the slide as I was accelerating off the face of the jump. I knew I was in for it so I jumped off and I landed 55 feet away from where I jumped off in a seated position. My head never touched the ground but I got knocked out for a short time from the jolt as it traveled up my spine.The bike just kept flipping end over end until it got stuck in the starting gate some distance away. It wasn't until some time later when I was feeling up to messing with the bike that I removed the carb and took it apart and saw the broken plastic pin had the slide stuck open. I never noticed in all the years I had them that they were plastic on those carbs. In all the other carbs on my bikes (round slide) other than the 78-80 CR 250R's the pin was part of the body.After finding the cause I inspected my 79 CR250R that I let my son ride at the time and you could see the locating pin on it was seeping around the edges. I fixed them both by making a new pin out of brass and epoxied it into the bore with a fuel compatible epoxy. I got busted up pretty dang good and ended up a good inch and a half shorter as a result and my back from my butt to my shoulders were black for the longest time from the bruising. My vehicles, bikes and just all my things in general are very well maintained but I have no one to blame but myself, I should have looked closer and payed more attention. I was lucky, it could have been so much worse. I had to give up riding moto but Im alive and I can still walk.... slowly. That's what counts. PS I miss riding and racing so freakin much Smile

John
roundtheoutside 12/29/2016 9:45am
12/29/2016 9:45am
Couple times in when it was freezing due to a little bit of water in the carburator (from the pressure washer I believe) No biggie, you grab the left lever instinctively. But my son once had a throttle stuck on his 16" 36V Oset and he smashed straight into the backyard shed WFO and that incident made me afraid of him having a stuck throttle on his sx 50 because these bikes don't have a clutch to pull in case. Horror of Horrors. Can't wait to put him on a 65
Tim507
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Tim507 12/29/2016 9:48am
12/29/2016 9:48am
Back when I was dumbass teenager - 60's into the early 70's...stuck throttles were a lot more common, then we discovered safety wire to wire the cable into the carb top and into the throttle assembly. That solved most of the problemsWoohoo Silly Whistling

Finally the Mfg'r figured out the problem.......

Lots of great memories for ever engraved into my memoriesCool
slipdog
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slipdog 12/29/2016 9:52am
12/29/2016 9:52am
I'm pretty sure Ricky Carmichael's throttle stuck every time he raced between 1997 and 2007, worked out pretty well for him though...

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Skidaddle
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Skidaddle 12/29/2016 10:11am
12/29/2016 10:11am
Way back in the day you expected it. No big deal. You should always be prepared.

In your vehicle more than anything. FBW can fuck up also.
crusher773
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crusher773 12/29/2016 10:12am
12/29/2016 10:12am
Mine got me a dislocated hip. It was due to an aftermarket aluminum throttle tube I put on.
656mx
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656mx 12/29/2016 10:15am
12/29/2016 10:15am
It happened to my son on his kx65. He had a little tip over and told me the throttle felt weird. I checked the grip, the tube, and revved it a few times. I couldn't find anything wrong. A few laps later I was walking across the track and I heard him on the throttle more than usual. By the time I turned around he was out of sight. The bike was screaming and he was screaming. He had launched over the berm, through the vines into the woods. I ran as fast as I could in full gear to the berm. He was standing next to the only big tree in there scared but ok. Some how he didn't get hurt. The cable had frayed at the carb and got stuck. He said it was a lot worse after I looked at it. If he had got hurt I don't know if I could of handled that. I should have checked the carb.
Skidaddle
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Skidaddle 12/29/2016 10:37am
12/29/2016 10:37am
roundtheoutside wrote:
Couple times in when it was freezing due to a little bit of water in the carburator (from the pressure washer I believe) No biggie, you...
Couple times in when it was freezing due to a little bit of water in the carburator (from the pressure washer I believe) No biggie, you grab the left lever instinctively. But my son once had a throttle stuck on his 16" 36V Oset and he smashed straight into the backyard shed WFO and that incident made me afraid of him having a stuck throttle on his sx 50 because these bikes don't have a clutch to pull in case. Horror of Horrors. Can't wait to put him on a 65
Why would you pull in the clutch anyway? That isnt stopping anything.


roundtheoutside 12/29/2016 11:56am
12/29/2016 11:56am
Skidaddle wrote:
Why would you pull in the clutch anyway? That isnt stopping anything.


It doesn't? It didn't stop the revving of the engine but by tapping the rearbrake it prevented me from launching myself into the bushes. fortunately it happend on a straight of the track, not in the whoops or in a tricky corner
milkbone117 12/29/2016 11:59am
12/29/2016 11:59am Edited Date/Time 12/29/2016 2:21pm
Tracktor wrote:
Wasn't there a recall/lawsuit due to carb plating or some such on YZ125's? Some dude got paralyzed if I remember?.......
There was definitely a recall on YZ125's, don't know the exact years but it captured the '01. I had my throttle stick and it almost ended badly.

It was in morning practice, sand track, so pretty wide open on the 125 to begin with...backed off the throttle coming into a turn and it just didn't stop pulling. It's easy to say grab the clutch (which I did) but when it happens you're so surprised the bike isn't doing what it always does, it takes a moment to piece it together. By the time I grabbed the clutch/brake I was already launching the berm. Thankfully it was sand meeting me when I eventually hit the ground!
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davis224 12/29/2016 12:08pm
12/29/2016 12:08pm
Sachmo831 wrote:
I had a 99 kx250 that would have a hanging idle issue through stutter bumps. It happened only a handful of times. Definitely a scary feeling...
I had a 99 kx250 that would have a hanging idle issue through stutter bumps. It happened only a handful of times. Definitely a scary feeling when you chop the throttle and it's still pulling!
My old boss was paralyzed from a 99 KX 250 sticking WFO on a parade lap before a steep jump face, after they brought the bike back to the shop to try and figure out what it was, I think they came to the conclusion the cases didn't seal right and would occasionally leak air
yak651
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yak651 12/29/2016 12:09pm
12/29/2016 12:09pm
Tracktor wrote:
Wasn't there a recall/lawsuit due to carb plating or some such on YZ125's? Some dude got paralyzed if I remember?.......
milkbone117 wrote:
There was definitely a recall on YZ125's, don't know the exact years but it captured the '01. I had my throttle stick and it almost ended...
There was definitely a recall on YZ125's, don't know the exact years but it captured the '01. I had my throttle stick and it almost ended badly.

It was in morning practice, sand track, so pretty wide open on the 125 to begin with...backed off the throttle coming into a turn and it just didn't stop pulling. It's easy to say grab the clutch (which I did) but when it happens you're so surprised the bike isn't doing what it always does, it takes a moment to piece it together. By the time I grabbed the clutch/brake I was already launching the berm. Thankfully it was sand meeting me when I eventually hit the ground!
Exactly, to those saying just grab the clutch hope it's that easy for you if it ever happens (actually hope it never happens to anyone). I'm a pretty "seasoned" rider/racer, won my share of chicken licks raceway events and it bit me, looking back I think the same thing as pretty much every picture of me has two fingers on the clutch, but for some reason that didn't work for me that day....
coastlinecascot 12/29/2016 1:19pm
12/29/2016 1:19pm
Happened to me once. I just learned since day one two have 1 finger on the clutch at all times. Just pulled in the clutch and let it rev until i hit the kill switch. It was a friends bike.
Barry_Smith 12/29/2016 1:36pm
12/29/2016 1:36pm
Tracktor wrote:
Wasn't there a recall/lawsuit due to carb plating or some such on YZ125's? Some dude got paralyzed if I remember?.......
milkbone117 wrote:
There was definitely a recall on YZ125's, don't know the exact years but it captured the '01. I had my throttle stick and it almost ended...
There was definitely a recall on YZ125's, don't know the exact years but it captured the '01. I had my throttle stick and it almost ended badly.

It was in morning practice, sand track, so pretty wide open on the 125 to begin with...backed off the throttle coming into a turn and it just didn't stop pulling. It's easy to say grab the clutch (which I did) but when it happens you're so surprised the bike isn't doing what it always does, it takes a moment to piece it together. By the time I grabbed the clutch/brake I was already launching the berm. Thankfully it was sand meeting me when I eventually hit the ground!
yak651 wrote:
Exactly, to those saying just grab the clutch hope it's that easy for you if it ever happens (actually hope it never happens to anyone). I'm...
Exactly, to those saying just grab the clutch hope it's that easy for you if it ever happens (actually hope it never happens to anyone). I'm a pretty "seasoned" rider/racer, won my share of chicken licks raceway events and it bit me, looking back I think the same thing as pretty much every picture of me has two fingers on the clutch, but for some reason that didn't work for me that day....
This. And this.

Happened to me on my '12 250SX. When you are riding on your limit and roll off the throttle late into a corner, or give the right amount of throttle for a given jump, then the bike itself goes WFO - there's not a lot you can do. For me, it happened twice in extremely critical sections and I had two BIG crashes.

Then even after it was "repaired" (complete rebuild, installation of a later model throttle and cable), it happened thrice more in non-critical sections.

Destroyed my confidence for a good while and I am still wary of KTM.
Motoxtombo
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Motoxtombo 12/29/2016 3:49pm
12/29/2016 3:49pm
When I worked at KTM shop years ago we had a kid have his throttle stick open on his KTM 125, We took the carb apart and found some dirt in the floatbowl, some dirt was keeping the needle from sliding back down in the carb body.
There was a inline fuel filter on the bike and the air cleaner was clean and installed correctly. The kid always pressure washed the bike,We think he blew some dirt up the carb overflow tubes causing the dirt in the floatbowl.

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