Khein carb idle adj question...pls help (94' CR 125)
EAL
What is the factory setting for the idle screw (all the way in and 2
turns out ????).
Do I turn it clockwise to make it richer?
Thanks in advance! :)
Merrill Hoekstra
Does this bike have the Keihin PWK or the PJ? The PJ idle adjustment is
in the choke circuit and is manipulated by raising the choke knob and
then spinning it. Counterclockwise increases idle speed. The PWK has a
separate idle screw coming out the left side (facing forward), while
these do affect the mixture slightly, that is not their main purpose.
You might be thinking of the "airscrew." It is a little slotted
screw on the side and toward the airfilter end of the carb. Turning this
counterclockwise (out) leans the mixture at small throttle openings by
allowing more air to pass through. Usually 1.5 turns out is the starting
point. If you need more than about 2.25 turns out, you need a leaner low
speed (sometimes called Pilot) jet.
If you really want to know about the idle screw, there is no "standard"
setting. I personally set my bikes to barely idle or not at all. I'm
less knowledgeable here, but I think high idles allow an overly lean
condition during higher speed sections where the throttle is closed.
Like descents or the end of a long straight. Plus fast idles may add
some power when you don't want it.
Good Luck, Merrill Hoekstra
--
Mandantory disclaimer follows . . .
"This content in no way reflects the opinions, standards
or policy of the United States Air Force Academy or the
United States government."
Matt Hennigar
edmund...@mindlink.bc.ca (EAL) wrote:
>What is the factory setting for the idle screw (all the way in and 2
>turns out ????).
>Do I turn it clockwise to make it richer?
In is richer and out is leaner
>Thanks in advance! :)
No problem
matt
@@@@@@@@@@@@@@@@@
@ I love my 89' KDX 200
@"Let the good times ROLL
@MATT Hennigar
@Canning NS, Canada
@ 2 strokes RULE And
@ 4 strokes just don't get me stroked
@@@@@@@@@@@@@@@@
Jeff@MX South
>If you really want to know about the idle screw, there is no "standard"
>setting. I personally set my bikes to barely idle or not at all. I'm
>less knowledgeable here, but I think high idles allow an overly lean
>condition during higher speed sections where the throttle is closed.
>Like descents or the end of a long straight. Plus fast idles may add
>some power when you don't want it.
>
>Good Luck, Merrill Hoekstra
>
I was reading Merrill's post to the '94 CR-125 idle question and wanted to
respond to a portion of it.
Why do people always say they set their bikes to "not idle"? Is that the
hip thing to say? Are we not real MX'ers or men if our bikes idle? What
is wrong with a correct idle, why does it have to be either fast or slow?
I'm not try to criticize you, Merrill. It's just that it seems like every
time I read something about carburation someone is saying to set your bike
to not idle. This seems like Troy's virus, a self perpetuating myth.
It is my experience that a bike that is set to not idle does not make the
mixture richer, like Merrill suggested, but in fact makes it leaner and can
be more dangerous than "adding some power when you don't want it", which is
definately a myth. Like when landing from a double and you need the power
on and the engine bogs or worse stalls because the engine starved itself
out of fuel because the slide was totally closed when you were off the gas
in the air. Just because your throttle is off doesn't mean your engine is
off, it is still running and going through it's cycle, it still needs fuel.
An engine always needs, no matter what rpm, a fresh and correctly mixed
(jetted) fuel charge in it to respond correctly.. An idle keeps the engine
fed with fuel as well as air. If a bike is leaning out on decents or long
straights then there is a problem with the jetting and not the idle.
Just my thoughts on something that has always bugged me.
Any comments?
Jeff
--
Jeff @ MX South
M...@usa.pipeline.com
305-255-3718
SBroon
Real men don't idle...it is true
Fast riders know that you need engine braking to get around corners
faster,
Idling disrupts engine braking.
Watch Windham or Emig on a video carefully in tight corners, preferably in
sand.
They will come in fast, fingers off the clutch, and lean the bike way over
while it slows itself just enough to make the corner. This allows for a
smooth turn, and a quick exit.
If they tried it with the idle set, they couldn't slow down.
Not using idle doesn't have anything to do with fuel mixture, it's
technique.
Try it!! It works!! If you don't believe me, go to a sandy track,
disconnect your clutch and turn down your idle and practice tight
corners....you will see.
PS I don't take credit for this, I learned it from a local Pro, Ricky
Palmer AMA#223.
Steve
The Factory Spectator
Mark Klein
I had a friend of mine talk me into trying it. I was under the
impression that no idle made you be on the gas sooner instead of
coasting through the corner. It seemed to work for me. I thought it
was a pretty neat trick myself. I don't do it on my woods bike,
though. I need to relax and rest as much as possible in my old age and
idling seems to help. And yes, I have the idle turned up on my
favorite arm chair.
MX Tuner
Jeff@MX South
Hey Steve,
I am a local pro level rider myself. I have been riding for 18 years and
sandy tracks are almost all we have here in FL.
I definately do not agree with your opinion on the no idle, engine braking
theory. I am not disputing the need for engine braking I use it myself.
Engine beaking still occurs if there is an idle. I am not talking about a
10 grand idle, I a talking about a normal low idle. An idle that will keep
your bike running long enough for you to put your goggles on on the line
without the engine stalling.
Now that I think about it an idle may not have anything to do with the
air-fuel mixture however, if the slide is completly closed, as it would be
if it were set to not idle, and the engine is still circulating it will
without a doubt hesitate or even bog when the throttle is opened again. It
is an engineering fact that it will starve itself out of fuel.
I believe that if you need such a drag from your motor to slow yourself
down then you need to work on your braking technique and skills more.
Myabe if your friend worked more on his braking technique he wouldn't have
a such a high 3 digit pro number. (Sorry, couldn't help it, I don't even
know who your freind is)
Steve, please fill me in on this one. What does disconnecting the clutch
have to do with entering turns. Do you coast into turns with your clutch
pulled in? If you do, then I understand why you are called the "Factory
Spectator".(again sorry, no offense, I'm not trying be rude)
It is going to be tough for you to convince me on this subject.
TMaxel
In article <4mfv2b$3...@news1.h1.usa.pipeline.com>,
m...@usa.pipeline.com(Jeff@MX South) writes:
> This seems like Troy's virus, a self perpetuating myth.
Thanks Jeff... I hadn't quite heard enough about it yet! :)
TMaxel
EMail -> MAXEL%MTC...@Navistar.com
95 & 96 KTM 50SXR
94 Cobra BM50
(It's my kids turn)
SBroon
Dude;
You miss the point entirely!
You write:
"I believe that if you need such a drag from your motor to slow yourself
down then you need to work on your braking technique and skills more."
I don't reccommend people watch me, I'm too slow. Watch Windham or Emig
in sandy or soft tracks. They rarely brake! They let the engine and the
sand slow them down at the last possible instant, and get through the
corner quickly and smoothly. If they were on the brakes, they would get
passed! Also, a bike that is set to idle won't work right if you try the
above, you will miss the turns.
The whole point in disconnecting the clutch is to practice this technique.
Everyone I know, including fast pros, has learned something. Don't knock
till you have tried it.
jfradaford@nwkjfr-8580
Rad>> You should have an Idle and Air/fuel mix screws. I generally set the
air/fuel mix screw out 1-1/2 turns, get the bike to idle, then turn
the air/fuel mix screw for the fastest idle, then adjust idle
screw till it runs just off the bottom w/o dying. I got this from
one of my shop manuals. This should work for any two or four stroke.
This may need to be repeated depending on the weather. Cold/hot/wet.
Air quality changes.
Jeff@MX South
Oh to the contrary Stevie baby,
I have ridden bikes without idles, Jet skis without idles, and ATV's
without idles and in all of the cases the the engines do not respond as
they should when the throttle is again turned on (the jet ski was almost
worth it 'cause they have no brakes). There is a lag or hestitation in
response and power because the engine starved itself while the throttle was
off. The trade off in response is not worth the minimal engine braking
that occurs, especially when light rear braking can achieve the same affect
and with more control. There is nothing worse then a dead spot when you
need instant power.
What point am I missing, Bud? We are talking about methods of slowing
down, right?
Lets see..."If they were on the brakes they would get passed" buddy, at the
speeds that they are carrying if you think they don't use the brakes and
are totally relying on engine braking to slow themselves down you are sadly
mistaken. Like I said I am from FL were we mostly have sand tracks and at
the speeds that I am carrying if I don't use the brakes I will be in the
weeds. Sorry, no matter what people say you still need brakes in the sand
(if your not up to speed the sand will stop you, but if you are crankin'
you will need brakes). Now if I am going fast enough to need the brakes
and I am nowhere near the caliber of the top pros then I know they need
more than engine braking to slow themselves down. Again, you make it sound
like brakes can only be locked on or completely off and nothing in between.
Also you still didn't explain what disconnecting the clutch has to do with
this. I am not an idiot, I know you were refering to practicing this
technique, but again how does disconnecting the clutch enable one to
practice engine braking? What does the clutch have to do with it?
Merrill Hoekstra
m...@usa.pipeline.com(Jeff@MX South) wrote:
>
>>If you really want to know about the idle screw, there is no "standard"
>>setting. I personally set my bikes to barely idle or not at all. I'm
>>less knowledgeable here, but I think high idles allow an overly lean
>>condition during higher speed sections where the throttle is closed.
>>Like descents or the end of a long straight. Plus fast idles may add
>>some power when you don't want it.
>>
>>Good Luck, Merrill Hoekstra
>>
>
>To: all,
>
>I was reading Merrill's post to the '94 CR-125 idle question and wanted to
>respond to a portion of it.
>
>Why do people always say they set their bikes to "not idle"? Is that the
>hip thing to say? Are we not real MX'ers or men if our bikes idle? What
>is wrong with a correct idle, why does it have to be either fast or slow?
>I'm not try to criticize you, Merrill. It's just that it seems like every
>time I read something about carburation someone is saying to set your bike
>
>Any comments?
>
>Jeff
I included what you qouted from me just to point out that I said, "I'm less
knowledgeable here," referring to my advice to set a bike to not idle. I
usually set up my bikes to where they will idle for about five seconds or so
then die. This is so I can adjust my goggles without an assistant.
Here is my understanding of the Keihin PJ carb, I might be wrong. When the
slide in this carb is completely closed (throttle off), the idle is maintained
through a completely separate circuit. This circuit includes an air passage
around the slide and a passage for fuel from the idle jet. Now, I *think* the
idle speed screw meters air, but does not meter the gas, which flows in a fixed
volume through the idle jet. The PWK carb seems to have a little needle type
setup that meters both fuel and air, but I think the PJ does not. (The PWK has
the D-shaped slide.) I could be wrong here, but it seems that setting anything
above the most minimum idle will allow the engine to run lean if the wheel is
turning for an extended period with the throttle completely closed, i.e. long
descents. This is especially the case in changing temperature and elevation
conditions. This is why I began setting for minimum-to-no idle when I raced in
the desert. My understanding of these carbs could be wrong.
The other reason I set for next-to-no idle is rideability. Maybe I'm just used
to it, but the extra little "push" I get from an idling motor going through slow
corners is an irritation. I have not noticed any hesitation in accelerating out
of corners. I would think that would be determined primarily by the slow jet,
the airscrew and the cut of the slide. Maybe I'll test this tomorrow at the
track by leaving these two adjustments where they are and experimenting with
different idle speeds. Who knows? I've been wrong before.
Merrill Hoekstra, Charter member r.m.d Denver SX spectator contingent
Eric Hollander
In article <4mg643$8...@newsbf02.news.aol.com>, SBroon <sbr...@aol.com> wrote:
>Real men don't idle...it is true
>Fast riders know that you need engine braking to get around corners
>faster,
>Idling disrupts engine braking.
i'm not a dirt rider or anything, but:
why not use the brakes for braking and the engine for going?
e
GraemeD
In article <4mdrq0$5...@usafa2.usafa.af.mil>, Merrill Hoekstra
<h.d...@banyan.usafa.af.mil> writes:
>If you really want to know about the idle screw, there is no "standard"
>setting. I personally set my bikes to barely idle or not at all. I'm
>less knowledgeable here, but I think high idles allow an overly lean
>condition during higher speed sections where the throttle is closed.
>Like descents or the end of a long straight. Plus fast idles may add
>some power when you don't want it.
>
>Good Luck, Merrill Hoekstra
Right on the money!
Graeme D. Denver Co. AMA 05684089
95' KTM 250SX
93' DR 350P
GraemeD
In article <4mj2lo$p...@news2.h1.usa.pipeline.com>,
m...@usa.pipeline.com(Jeff@MX South) writes:
>
>It is going to be tough for you to convince me on this subject.
>
>Jeff
Yo Jeff, none of my 2 stroke bikes idle! The reason I do that is to get
the jetting better (and it started when I was riding 500's they put out
more at idle than most 80's do on the pipe!)) you get a much cleaner
throttle chop , it dosn't go ring ding ding. and I have always rode it the
woods. I set it so as to let it die after a second or two. just long
enough to pull my goggles on on the line ( maybe with one rev in between)
Ask Wiiaim Thompson about his RMX that he could not get jetted right. once
we turnrd the idle down it ran fine.
PS: rode a Killer enduro in Nebraska last weekend!
GraemeD
In article <4mm8lg$7...@news2.h1.usa.pipeline.com>,
m...@usa.pipeline.com(Jeff@MX South) writes:
>Also you still didn't explain what disconnecting the clutch has to do
with
>this. I am not an idiot, I know you were refering to practicing this
>technique, but again how does disconnecting the clutch enable one to
>practice engine braking? What does the clutch have to do with it?
>
it allows you to pratice starting the bike on the track and running with
it to get it moving!
SBroon
Because it works! Some of the fastest pros use a technique to get around
corners on soft or sandy tracks that involves little or no braking, no
clutch, and engine braking. Some people seem skeptical, but it is true
and it works.
Watch a video of Kevin Windham on a sandy track, he can get through
corners faster and smoother than anyone I have ever seen. He hardly slows
down at all, and just dives into the next corner, allowing the engine to
slow him down just the right amount. This is one fluid motion. To do
this you have to lean way over, and if your bike is set to idle, it
doesn't work very well.
Steve
TFS
$3 Bill
Merrill Hoekstra wrote:
>
> m...@usa.pipeline.com(Jeff@MX South) wrote:
> Merrill Hoekstra, Charter member r.m.d Denver SX spectator contingent
>
> --I agree with the close to no idle opinions. Properly done it definately
helps me (a novice MXer) deal with the option of slowing down for turns
and such.
RMD Denver SX spectator and tail gate party contingent. Look for the
green 4x2 ranger xtra cab with the charcoal primed on premix.
richard...
Mike Baxter
gra...@aol.com (GraemeD) wrote:
>Right on the money!
>Graeme D. Denver Co. AMA 05684089
>95' KTM 250SX
>93' DR 350P
Agree.
Agree.
Now! I still believe that it doesn't matter what you set the idle at.
I don't like my bike to die. I use my clutch to feed power to the
rear wheel on bikes. So it doesn't really matter where I set the
idle.
Later,
___________________________________________________________
Mike Baxter "Nobody reads .sig files anymore.
baxter...@whytel.com What is the net coming to?!"
******** 1996 XR400R DP ********
Aaron Mefford
Richard, Merrill and anybody else who cares to respond:
I have trouble with the no idle concept-actually a specific problem. When descending, particularly steep stuff, sometimes I pull in=
the clutch to keep from stalling the bike. With the no idle set-up, I of course forget to rev the bike when I pull in the clutch, =
and yeah, I stall it anyway. Now I've got a KTM 440 careening down a hill with a tranny that doesn't want to upshift to bump start =
it, and things just get uglier from there. I personally have cured the problem by setting up the bike to idle. This has allowed me=
to move beyond this particular blunder into some other interesting geek/bonehead moves. I'm perfectly willing to retune my bike to=
no idle and try any reasonable suggestions, though. Most of my current crop of bruises have healed. Please don't just blast me on=
this one, but if you have any seriuos (or particularly funny) suggestions, by all means, let me know. Thanks or hose off in advanc=
e, depending on the sincerity of the suggestion.
Cheers,
Aaron!
GraemeD
In article <4muecv$d...@news.csus.edu>, Aaron Mefford <amef...@csus.edu>
writes:
>Richard, Merrill and anybody else who cares to respond:
>
>I have trouble with the no idle concept-actually a specific problem.
When
>descending, particularly steep stuff, sometimes I pull in=
> the clutch to keep from stalling the bike. With the no idle set-up, I
of
>course forget to rev the bike when I pull in the clutch, =
>and yeah, I stall it anyway. Now I've got a KTM 440 careening down a
hill
>with a tranny that doesn't want to upshift to bump start =
>it, and things just get uglier from there. I personally have cured the
>problem by setting up the bike to idle. This has allowed me=
> to move beyond this particular blunder into some other interesting
>geek/bonehead moves. I'm perfectly willing to retune my bike to=
> no idle and try any reasonable suggestions, though. Most of my current
crop
>of bruises have healed. Please don't just blast me on=
> this one, but if you have any seriuos (or particularly funny)
suggestions,
>by all means, let me know. Thanks or hose off in advanc=
>e, depending on the sincerity of the suggestion.
>
>Cheers,
>
>Aaron!
I have no problem with steep hills, I just modulate the rear brake, and
use the front more, the rear is almost useless on steep downhills
Graeme Davies AMA 568408
Denver, Co FTR 6-29654
95' KTM 250SX RMEC 2131
93' DR 350P
Jeff@MX South
On May 07, 1996 18:20:39 in article <Re: '94 CR-125 jetting,The old "no
Jeff@MX South
On May 08, 1996 01:07:32 in article <Re: The old "no idle" myth, lets go
baby!>, 'gra...@aol.com (GraemeD)' wrote:
>In article <4mm8lg$7...@news2.h1.usa.pipeline.com>,
>m...@usa.pipeline.com(Jeff@MX South) writes:
>
>>Also you still didn't explain what disconnecting the clutch has to do
>with
>>this. I am not an idiot, I know you were refering to practicing this
>>technique, but again how does disconnecting the clutch enable one to
>>practice engine braking? What does the clutch have to do with it?
>>
>
>it allows you to pratice starting the bike on the track and running with
>it to get it moving!
Jeff@MX South
On May 07, 1996 15:01:21 in article <Re: '94 CR-125 jetting,The old "no
idle" myth>, 'Merrill Hoekstra <h.d...@banyan.usafa.af.mil>' wrote:
To all:
This is definately my opinion, but I feel strongly about it. I'm not to
sure why, maybe because it's late and I'm tired of getting hammered on
this subject, but here are some good points for you guys to mull over.
Some people have said that there is better throttle response when the slide
is all the way closed and no idle (Graeme). And others say that the
mixture will lean out if the slide is open a little with the idle set
(Merrill). Oh yea, and don't even get me started on that clutch
disconnecting garbage again (Steve) !
Well. check this thought out guys... Neither is true! (I am not attacking
anyone, I am just discussing a point) If your idle is set properly and
your bike is either rich or lean at idle or low speed, then your jetting is
off, not your idle ! Like Merrill was pointing out the PJ is a little
different (the principle is still the same), but most other carbs are
designed the same when it comes to an idle. The idle is simply a device
that opens the slide just like the throttle does. If your idle is set
right your bike WILL respond better (that is if your jetting is right !),
it has to because the idle is a "head start" for the movement of the
throttle. And moreover, if your engine is already at a 1000 to 1500 rpm
idle that is a better starting point for throttle response than 100 to 300
rpm (an idle gives you a higher starting point for the beginnig of your
throttle response).
Merrill suggested that a long downhill could lean out an engine if the idle
is set. I agree with this if the jetting is off, but if the jetting is
right then this WILL NOT happen. It is my contention that a closed idle
will lean out an engine in this situation. Because along with stopping the
air flow with a closed idle you are also stopping the fuel flow. If ther
is no air flowing over the jet openings there is no vacuum to pull the fuel
out of the bowl of the carb and into the engine. If the engine is still
circulating, as it would be when going down a hill then it will continuosly
need a steady supply of fuel mixture to keep it from leaning out. If the
throttle is open a bit, as it would be if the idle were set, yes more air
will be flowing in but!, so will more fuel if your low speed jet, slide
cutaway. and beginning straight portion (diameter) of your needle are all
correct. This will feed the engine the correct fuel/air mixture that it
desperately needs in a long downhill section to keep from leaning out.
I know someone will say that if the throttle is closed all the way the
engine will suck fuel straight out of the pilot jet hole and into the
engine to keep it from leaning out if it is still circulating when going
down a hill with the throttle off. Well since when is dumping raw
unatomized fuel directly into the engine good carburation?? You can't
possibly argue that as conducive to good throttle response or anything else
good for that matter, except fowling plugs.
That's enough venting for now I going to sleep!
Jeff
GraemeD
In article <4n18o7$b...@news2.h1.usa.pipeline.com>,
m...@usa.pipeline.com(Jeff@MX South) writes:
>>it allows you to pratice starting the bike on the track and running with
>>it to get it moving!
>
>Oh shit ! Now that is important ! Thanks Graeme, buddy.
No problem, anytime Jeff,
SBroon
I do not like new ideas
I do not like them Sam I Am...
I don't try them
I don't need them
I do not want them Sam I Am....
GraemeD
In article <4n1cvl$j...@news2.h1.usa.pipeline.com>,
m...@usa.pipeline.com(Jeff@MX South) writes:
>That's enough venting for now I going to sleep!
>
>Jeff
>--
>Jeff @ MX South
>M...@usa.pipeline.com
>305-255-3718
>
>
NOT so Quick snooze hound!
Check out the article written by FMF's Terry Varner in the March Dirt
Rider page 93, and I quote
"Always set the idle when the bike is up to normal operating temperatures
and start with the high idle. Slowly creep down until the engine dies and
then go a quater -or half turn past that"
Good article, Read it!
Michael Patrick
I've got to admit that I've never been as fast as anyone on any of the
factory teams (never will be) but a majority of them use 'no idle' on
their bikes. This according to the factory wrenches allows for crisper
throttle response. I know that Mark Barnett turns the idle all the way
off on all of his bikes when he gets them. His attitude is that you
shouldn't be locking up the rear wheel unless your hand is on the clutch
and throttle to blip it... just a thought.
My opinion though... I like my bikes to idle a little high, just a
personal thing you know.
Mikeee P
$3 Bill
_Green Bikes and Spam_ By Dr. Sue-us.
You know, this thread and this subject is, like, so gone. It's like I am
so over it, you know? For sure!
richy...
Steve Fortner
In article <4n5q3g$e...@newsbf02.news.aol.com>, gra...@aol.com (GraemeD) wrote:
<snip>
> Check out the article written by FMF's Terry Varner in the March Dirt
> Rider page 93, and I quote
> "Always set the idle when the bike is up to normal operating temperatures
> and start with the high idle. Slowly creep down until the engine dies and
> then go a quater -or half turn past that"
>
> Good article, Read it!
>
> Graeme Davies AMA 568408
> Denver, Co FTR 6-29654
> 95' KTM 250SX RMEC 2131
>
> 93' DR 350P
Graeme, so what is the reason for doing this? Does it lean out the
mixture or what???
--
Steve Fortner
92 RM 125
Joshua H
> In article <4mg643$8...@newsbf02.news.aol.com>, SBroon <sbr...@aol.com> wrote:
> >Real men don't idle...it is true
> >Fast riders know that you need engine braking to get around corners
> >faster,
> >Idling disrupts engine braking.
> i'm not a dirt rider or anything, but:
> why not use the brakes for braking and the engine for going?
> e
Volker Bartheld
such little ones as the CR125R - have zilch, zero, nada, null engine
braking and might even seize if operated for prolonged times at
elevated revs with the throttle closed.
My 1994 CR250R _did_ idle, of course. As long as I wanted it to. Because
air filter and carb were clean, bike jetted properly and I was running
decent premix. 1:50 fully synthetic IIRC.
Volker