Throttle stuck WFO on a 2-stroke

jgmxdad251
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jgmxdad251 12/29/2016 4:23pm
12/29/2016 4:23pm
I had a clutch cable break. Replaced it, did a hill climb after adjusting the cable. Hit a set of whoops in third and shifted to fourth after the last whoop and my bike stayed pinned in fourth. I ended up letting go of the bike because I was headed for a corner with a 150 foot cliff. Bike made the corner then slamed to the ground breaking my oversize bars while staying pinned. It's amazing how fast you can run when you think your bike is going to blow up. Ended up being a frayed cable being stuck between the throtle housing and cable wheel. No injuries on that one but, I compiled a pretty long list on another bike that the throtle stuck on. Learned my lesson, check my cables all the time now.Cool Cool
MaxPower
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MaxPower 12/29/2016 5:34pm
12/29/2016 5:34pm
Mine stuck on a 02 YZ125. I got hurt pretty badly. I've had plenty of people say just pull the clutch, and they are right. But it happens so quickly with zero warning that I just didn't react that way. I sold that bike and never rode it again
Greenbush
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Greenbush 12/29/2016 5:56pm
12/29/2016 5:56pm
I used to always run inline fuel filters on my 2 t bikes then on my ktm 250 I was having situations when I thought the throttle was sticking.
Come to find out the filter was plugging up and causing lean run on situation. Had a hard time figuring that one out.
Finally did when I drained the tank one day and noticed the fuel flow was just a dribble.
dboivin
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dboivin 12/29/2016 5:59pm
12/29/2016 5:59pm
i pulled in the clutch.....

The Shop

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omalley
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omalley 12/29/2016 6:58pm
12/29/2016 6:58pm
Back in my 250 (two-stroke) beginner days I raced a mud race at SIR (now pacific raceways). Between motos one of my competitors decided to use the track's fire-hose style nozzle to wash his bike. He must've flushed a bunch of sand into the carb and/or throttle as on the start, we were all braking for the first turn and there he goes, sailing on past the first turn and into parts unknown. Weird feeling to be in a pack, all slowing for a turn, and see someone WFO still going straight...thankfully for us he was on the outside...
RCMXracing
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RCMXracing 12/29/2016 8:56pm
12/29/2016 8:56pm
Yep. 2002 CR 250R. Oberg aluminum throttle tube with a bearing in the end. Well engineered piece, felt very connected. Unfortunately the flang/cam where the cables connect was rubbing on one side inside the throttle tube housing. I got launched ballisticly off a jump and nose dived back down to earth. Walked away. Very lucky. I won't run an aluminum tube to this day.
mxrose3
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mxrose3 12/29/2016 9:32pm
12/29/2016 9:32pm Edited Date/Time 12/29/2016 9:35pm
Yamaha had a rash of stuck throttles back in 99' or so.... Jeff Emig had to retire because of it.
The problem was the round pulley inside the throttle - if the cable had any slack, it could come out of the groove and get stuck. They put a new style pulley inside the throttles in 2002 or so if I remember right.

http://dirtrider.net/forums3/threads/danger-yamaha-recalls-throttle-pul…
RatCityMX
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RatCityMX 12/29/2016 10:05pm
12/29/2016 10:05pm
omalley wrote:
Back in my 250 (two-stroke) beginner days I raced a mud race at SIR (now pacific raceways). Between motos one of my competitors decided to use...
Back in my 250 (two-stroke) beginner days I raced a mud race at SIR (now pacific raceways). Between motos one of my competitors decided to use the track's fire-hose style nozzle to wash his bike. He must've flushed a bunch of sand into the carb and/or throttle as on the start, we were all braking for the first turn and there he goes, sailing on past the first turn and into parts unknown. Weird feeling to be in a pack, all slowing for a turn, and see someone WFO still going straight...thankfully for us he was on the outside...
What year was that? It may have been me I had a YZ250 and I didn't turn the gas on and it would lean out and go WFO. I went filling off the first turn and landed on the tires got it started and rejoined the race. I think that was the only time I got a Hole Shot.

I know there is a previous thread on this but thank you to Vital guys for doing this I read all the time and it always brings a smile or a laugh.
Jspazz
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Jspazz 12/29/2016 10:42pm
12/29/2016 10:42pm
Had it happen on my TL1000 road bike at Calabogie on the big straight. Caused me to miss my braking marker by 50 feet from 250 km/hr, almost t-boned a guy who was turning in while I went straight on to the grass. I managed to keep it up, and went out to finish the lap and pull in - and it happened again on the next straight, so I limped to the pits really slowly to figure it out.

Took me over an hour to understand - I forgot to zip-tie the rad fan cable, and it was jamming the throttle linkage WFO at any speeds over 3rd or 4th gear because of the wind pushing it back. Cursed myself for overlooking this when I was building the bike the week before.

I know it isn't a 2-stroke, not even carbs, but I just wanted to add my case to the ones where inattentiveness or poor maintenance can cause disaster. Be careful out there.
Turbojez
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Turbojez 12/29/2016 11:42pm
12/29/2016 11:42pm Edited Date/Time 12/29/2016 11:51pm
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!
That's exactly the situation I had. Sandy track, staying on the gas until in the turn, closed the throttle but the bike would just keep on pulling so i launched from the berm and into the sky. I tried to leave the bike before jumping, but did it just a little too late and ended up flying right behind the bike with my feet pointing straight into horizon. Landed flat on my back, 6 months off of riding, backplate of the chest protector broken into pieces. Some disc damage, was rather painful.

The reason I asked the question in the first place is I started thinking about switching from my old 250f to a 2-stroke suzuki 250, but I have to admit that my past experience with 2 stroke is kinda making me think twice about it. The throttle return cable on a 4-stroke gives you that peace of mind...
HenryA
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HenryA 12/30/2016 12:18am
12/30/2016 12:18am Edited Date/Time 12/30/2016 12:21am
KTM had huge problems with this a few years ago

http://blog.motorcycle.com/2013/04/23/manufacturers/ktm/2013-ktm-two-st…

I've raced on 2-strokes for years and never had the throttle stuck even once. It did experience it once as a kid, but it was on the old pig aka Honda XR80
swed9418
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swed9418 12/30/2016 1:25am
12/30/2016 1:25am
Did happen to me two times. ( ktm 150 sx)

Last time it did I was going down a hill 4 gear wide open, I remember the jump at the bottom of the hill was pretty steep and after that I was sent flying. I would probably had benefitted to have had a parachute. Smile
Jack_Wagon
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Jack_Wagon 12/30/2016 4:43am
12/30/2016 4:43am
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!
davis224 wrote:
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...
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
I've got a plate in my right arm from a 99 KX250. We never could figure out what caused the throttle to stick. I had the bike at a local shop for a second opinion, and it did it again while on a stand. They determined it had an air leak between the center cases too.
Marc_Honda 12/30/2016 4:53am
12/30/2016 4:53am
Not a lot you can do, even the best riders would have problems.

If it's a mile long straight then I think it would be OK but as soon as panic sets your brain stops functioning properly, especially when all you're thinking about is getting hurt.
Thisusernameisavailable 12/30/2016 6:41am
12/30/2016 6:41am
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!
davis224 wrote:
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...
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
Another '99 KX250 here.

Id had the bike from new with no issues. One day out for practice on a small private SX track, I warmed the bike as normal, took to the track had 1-2 laps on the pegs, then the first time gave it a handful it didn't shit off- the next jump through me in to air, breaking my femur along with the opposite ankle and various other smaller injuries.

Prior to this ride I hadn't done anything mechanical to the bike other than wash, air filter prep and gear oil. There really was no reason for it to do it.

After recovery, I took the carb off, cleaned it, checked everything, nothing abnormal showed up.
The next ride, I stick open again!! Luckily this time on an uphill straight- so no dramas. I pulled over, revved the bike a few times and it was behaving normally again.

I took it home, washed it and took it straight to the local kawasaki dealer and done a p/x on a new 2000 model KX250. Which never ever caused me a problem.

Weird shit.. Interesting to hear these other issues with 99 kx250s!
wfo4ever
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wfo4ever 12/30/2016 7:15am
12/30/2016 7:15am
That is exactly how you ride a 2-Stroke. Keep the throttle in the "WFO" position at all times!!! If you have anymore 2-Stroke questions, just contact wfo4ever.

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