How to kill a runaway 2-stroke?
Mark Lechowski
OK , its not the first time this happened to me and not only on this bike.
I try and fail a hill climb at which point me and my bike get separated and
the bike just lays there with the throttle grip nicely buried in the mountain
and the motor just rapps out of control at about 10 - 12,000 RPM.
I run to the bike and nail the kill button. Hold it down for about 10sec.
Nothing.....
I feel pretty brave ( or panic ) at this point so I grab the plug wire
pull it of the plug ( zapp,zapp,zapp ) get thrown down the hill a little
and the bike , you guessed it, still revving out of control. I run back up
and see the plug wire about six inches away from the plug and violently
discharging a massive amount of sparks too the side of the cylinder.
At this point I start doubting anything I know about elctricity or an
operation of a motor and resort to the only option I can think of and kick
my foot under the still powered and very fast spinning rear wheel in hopes
of slowing the motor down enough to get it out of the ppower band and eventauly
dying out.
Well it works. My foot got bruised but thats better than a seized motor.
Oh, I should also say I broke my handle bars on that last dump and the throttle
cable was crushed, in the wide open position of course.
How do you kill that damn motor in a situation like that?!
Whats going on?! How can the plug wire be discharging to ground(motor) and
the engine still run like it was getting a spark the whole time?
Any clues on prevention?
Any and all suggestions appreciated.
Mark L.
Andreas Meyer
while it's in a tall gear. You should be able to stall it.
I don't know about your electrical problems though. I've never experienced
anything like what you describe.
Andreas
Jeremy Hansen
: How do you kill that damn motor in a situation like that?!
: Whats going on?! How can the plug wire be discharging to ground(motor) and
: the engine still run like it was getting a spark the whole time?
The only time I had something similar happen to me the only way I could
get it to die was to put enough load on the engine to get it to stop
(my runaway 2-stroke happened in an out-of-gas incident with me on top.
First time I'd even ridden a dirt bike, and this thing just starts running
off with me at full speed. Kill button? Didn't help. I kept upshifting out
of fear of blowing up the engine until I just bit the bullet and smashed
the rear brake as hard as I could.) So my guess is stopping the rear
tire is the way to stop the motor. As far as what's going on, I would
guess that the heat and RPMs combine to create a situation where you
don't need a spark plug to combust the gasses anymore, something perhaps
like Honda's future 2-stroke engine, or a diesel for that matter..
--
Jeremy Hansen jer...@amcc.com
Technology Group
Applied Micro Circuits Corp.
AMCC now has a web page: http://www.amcc.com/
mitchell r. baghdoian
Similar thing happened with an old yz250 my buddy had. What is happening is that at those high rpms the motor doesn't need a spark to combust the fuel- the heat and pressure will do it by themselves. Yes, your bike is dieseling. To shut it off you have to reduce the rpms somehow- safest way is to hit the rear brake (impossible, of course, since the reason the throttle is pinned wide open cuz it's laying on its right side to begin with). Grab the handlebars and lift the bike so the rear tire grabs- the rpms
will drop enough so the motor will quit. Make sure your finger is on the kill switch or you're gonna watch it happen again.
BTW, if you use bark busters there is a very slim chance of the throttle pinning itself open.
Mitch in MI
90 KDX200
86 ZX600R
[Maher Maso, Plano Tx.]
>
> OK , its not the first time this happened to me and not only on this bike.
> I try and fail a hill climb at which point me and my bike get separated and
> the bike just lays there with the throttle grip nicely buried in the mountain
> and the motor just rapps out of control at about 10 - 12,000 RPM.
Solution: Don't get seperated from your bike. Everytime I have ever tried
to seperate from my bike, it hurt me more than the bike.
>
> I run to the bike and nail the kill button. Hold it down for about 10sec.
> Nothing.....
The kill button should <always> kill the bike. You didn't mention if the bike
"sputtered" at all during the 10 seconds or the button had no effect. I'd check
the button real close and replace it if necessary.
> I feel pretty brave ( or panic ) at this point so I grab the plug wire
> pull it of the plug ( zapp,zapp,zapp ) get thrown down the hill a little
> and the bike , you guessed it, still revving out of control. I run back up
> and see the plug wire about six inches away from the plug and violently
> discharging a massive amount of sparks too the side of the cylinder.
> At this point I start doubting anything I know about elctricity or an
> operation of a motor and resort to the only option I can think of and kick
> my foot under the still powered and very fast spinning rear wheel in hopes
> of slowing the motor down enough to get it out of the ppower band and eventauly
> dying out.
Brave (but...) on both counts. I'm surprised sticked your foot under the tire
did the trick! A full-on 2-stroke is nothing to sneeze at. I had fun with my
son's pw-80 when the throttle stuck on that. Threw me to the ground twice
while I was trying to hold it. I wonder if throwing the choke on would help?
Shutting off the fuel would take too long. How about plugging the exhaust? I
know that when I forget my pipe plug in, my bike won't run :-)
> Any clues on prevention?
>
> Any and all suggestions appreciated.
>
> Mark L.
>
>
>
================================
* mm...@ibm.net ! OS/2 !
* tccra #77 ! !
* 95 WR250 ! !
================================
donwi...@earthlink.net
lechowsk@PROBLEM_WITH_INEWS_GATEWAY_FILE (Mark Lechowski) wrote:
> OK , its not the first time this happened to me and not only on this bike.
> I try and fail a hill climb at which point me and my bike get separated and
> the bike just lays there with the throttle grip nicely buried in the mountain
> and the motor just rapps out of control at about 10 - 12,000 RPM.
>
> I run to the bike and nail the kill button. Hold it down for about 10sec.
> Nothing.....
> I feel pretty brave ( or panic ) at this point so I grab the plug wire
> pull it of the plug ( zapp,zapp,zapp ) get thrown down the hill a little
> and the bike , you guessed it, still revving out of control. I run back up
> and see the plug wire about six inches away from the plug and violently
> discharging a massive amount of sparks too the side of the cylinder.
> At this point I start doubting anything I know about elctricity or an
> operation of a motor and resort to the only option I can think of and kick
> my foot under the still powered and very fast spinning rear wheel in hopes
> of slowing the motor down enough to get it out of the ppower band and
eventauly
> dying out.
> Well it works. My foot got bruised but thats better than a seized motor.
> Oh, I should also say I broke my handle bars on that last dump and the
throttle
> cable was crushed, in the wide open position of course.
>
> How do you kill that damn motor in a situation like that?!
> Whats going on?! How can the plug wire be discharging to ground(motor) and
> the engine still run like it was getting a spark the whole time?
>
> Any clues on prevention?
Mark,
Use your boot or (gloved) hand or whatever is handy to plug the exhaust
pipe. Turning it upside down will also run it out of gas, but this isn't
as quick a method as the first one (but if you have a Supertrapp it may be
your last resort).
- Don
Andreas Meyer
take a while longer for it to stop running, but eventually it will. Best
bet still is putting the bike in gear and applying rear brake though.
Andreas
Jerry Gomez
It happened to me once down in Rosarito Beach on my ATC. I was running a little lean and running out
of "on" gas. I first thing that came to mind was the engine ON (ignition) switch, NO, it did not
stop!!! after I switched it OFF. It was igniting anyway. Second thing I tried was up shift really
quick and slam on the rear brakes and that shut it off. I was afraid I would seize it, but I don't
run Wiseco so no damage at all :-) I put it on reserve and drove it back... This happened two years
ago and my 250R still runs perfect.
Jerry
Thomas F Kirk
with a hot spot of carbon (or whatever) in the cylinder.
If you can remove the cylinder head you'll be able to verufy
that a carbon buildup is causing the problem.
Tom Kirk
Roswell, GA
DoD #1791
--------------------------------------
J. Mangimelli
I experienced the same thing on my first trip to Pismo. I was riding my
cousins old YZ250 and pulled up next to him on his new bike. When I
stopped the carb got suck or something and the engine started whining up
in to high RPMs. I hit the kill switch..nothing....Pulled the spark
plug....nothing....Only thing left was to stall it. So I upshifted to 2nd
and it lurched, but quickly died. I still thing I have hearing damage ;)
David W. Taylor
Every played with a model airplane motor?? Your motor is going into
a glow-plug cycle and running without spark. If your not racing
and have the correct opening in the head you might install a compression
release.
Any other opinions??
Dave Taylor
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
David Taylor Office Phone (503) 642-8563 Work 8:30am til 9:pm FRI,SAT,SUN
DOD#979 93'DR350S/57'Ford 500/69'Porsche 911T/94'Wrangler
I bet the victims of Genus Khan dont believe "Violence never solved anything"
History is written by the victor.......(if you know who wrote this e-mail me)
My opinions are mine ,,NOT Intel's and nobody elses(Jeese whod wantem anyway).
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Tim Simmons
rev out of control when first started.
It scared the shit out of me the first time (I was about 12 years old),
I finally ended up just pulling the carb out since it was rubber mounted
on both ends it was fairly easy to do. It stopped running almost instantly!
--
_______________________________________________________________________________
Tim Simmons - Opinions expressed above are mine, not my employer's
Auspex Systems - The World's Best NFS Servers
donald dieterich
You will not damage aan engine if you just jam it in gear and drop the
clutch with the brake on.... This is no more punishment than when
bike start a race... Even if you have a Weisco... I run a Weisco in
my 310 on Meth Alcohol, sit on the line full throttle and drop the
clutch, if I had the brake on it would stall and not hurt a thing...
But i dont have the brake on, so I just through sand at banshees...
Jerry Gomez
All Banshees?
Donald,
How expensive is it to 310 my ATC250R? I want to still run pump 92-93
gas, so the compression can't be that high. I was thinking $1,000. I
need the cyl, head, and larger carb. Did you get yours from CT?
Jerry
LAWHOSER2
your
on the brake really good...my kx250 got away from me once and it aint fun
wrestling a bike on the ground in a spin !!!!!.....just make sure your
bike isnt
aimed at someone or something you dont want to destroy!!!!...
steve sherman
LAWHOSER2
happen on
older bikes ( I had it happen on my ' 88 kx250...!) is the throttle valve
being worn
at the bottom where it seats in the carb. Check the valve next time you
have the
carb apart ...especially on older kx's!!!..it may have worn and can/will
get stuck
open eventually and will cause the run-away blues!!! new throttle valves
are now
chrome plated to prevent the valve from wearing and causing this dangerous
condition. If you have an older bike and it seems to want to "run-on" when
you
let off the throttle...this could be a sign of this condition ...so check
it out immediately!!!!....you dont want to come up to that "table-top"
jump at full throttle
with it stuck!!! i had it happen...and evil kenievel i did not want to
be!!!...good luck!
steve sherman
' 88 kx250
Grego200
(LAWHOSER2) writes:
>Subject: Re: How to kill a runaway 2-stroke?
>From: lawh...@aol.com (LAWHOSER2)
>Date: 14 Nov 1995 15:22:36 -0500
Like a Dodge Power Wagon perhaps???? :')
Eric Neria
Eric