Okay so I finally grew out of my 125 a while back and decided to get a 250. I came across a good deal for a 96 (wish it was newer :/). So any ways...the bike runs great, couldn't wish for more...but it does not idle at all! I know that letting a 2 stroke idle a while=fouled plugs but i have to constantly give it gas so that it wont cut off. Ive heard that i just need to jet my carb. any ideas any one?? -thanks
not idling at all....need help!
- Thread starter 96CRkid
- Start date
You can adjust the idle screw until it idles a little bit.. But more than a few seconds isn't good.
I never do understand why people want their two stroke to idle, it's serves no purpose at all.
Four strokes I get, they're a bit harder to start. But a properly maintained two stroke should start on the first or second kick, every time. If it's not, there's something wrong with it that needs to be fixed.
If it's not idling, but running fine otherwise, it's how it should be. It doesn't need to be fixed.
I never do understand why people want their two stroke to idle, it's serves no purpose at all.
Four strokes I get, they're a bit harder to start. But a properly maintained two stroke should start on the first or second kick, every time. If it's not, there's something wrong with it that needs to be fixed.
If it's not idling, but running fine otherwise, it's how it should be. It doesn't need to be fixed.
I beg to differ on the benefits of a two stroke that idles. It's often more convenient if it will keep running when you have to make a quick stop to clear a trail, help a downed rider or defog your goggles. The four two strokes that our family has owned, YZ125 & 250, KTM 125 and CR250 have all idled well. At the end of a day of riding, we'll turn off the petcock and just let them idle until the floatbowl is dry while we take off gear and load other stuff. All it takes is proper jetting and correct float height. We've never had issues with plug fouling from extended idling.
I know that lots of racers like their two strokes to die when they're not moving, but I've not heard an explanation for it, other than "just because." Not being a racer, I can't offer a rebuttal to that. Anyway, I believe that time spent jetting is not wasted and it brings the satisfaction that the bike is performing to its potential.
I know that lots of racers like their two strokes to die when they're not moving, but I've not heard an explanation for it, other than "just because." Not being a racer, I can't offer a rebuttal to that. Anyway, I believe that time spent jetting is not wasted and it brings the satisfaction that the bike is performing to its potential.
slodad said:
Beg all you like, you are wrong sir.
Let me offer an explanation again.
If you idle your two stroke, you will tend to foul the plug easier.
Again, it's so easy to start a 2 stroke that idling is not something that you should even worry about.
And your method of draining the carb is wrong also. If you are running the bike out of gas with your method, you are running it way lean every time. That's not good for the engine. It is way better to drain it with the plug on the bottom of the float bowl. That's what it's there for.
rmc_olderthandirt
~SPONSOR~
- Apr 18, 2006
- 1,533
- 8
It is certainly possible for a two stroke to idle and not foul plugs. I have a two stroke outboard and a pair of two stroke PWC and they will idle all day long.
After a lot of fiddling I finally managed to get my YZ-125 to idle, most of the time...
I am still working on the WR-250.
To me, it is really important that the bike idle, at least for a minute, and especially when it is hot. When I am riding really difficult terrain and need to creep over some obstacle, especially down hill, it is a real pain to have the engine die. After you have been riding 60 miles of difficult goat trails the extra effort to start the bike becomes an issue.
If you just ride at the MX track I suppose it wouldn't matter too much, as long as the engine doesn't die mid jump.
To get the engine to idle the first thing you want to do is make sure you don't have any air leaks. This would include crank seals. While you are at it check the reeds and make sure they are in good shape. Minor leaks or minor reed warpage won't bother top end much but it will be hell on the idle.
Next step would be to clean the carburetor and make sure the float level is correct. If the float level is off you may never get a good idle and changing the float level may change the idle characteristics.
Once everything else is proper then it is time to make adjustments on the carburetor. There will be two screws that you are dealing with. One adjusts the idle speed and the other adjusts the mixture.
Start with the bike warmed up to normal operating temperature.
Set the idle speed to whatever it takes to get it to idle. Now adjust the mixture screw to get the fastest idle.
Now adjust the idle speed a bit slower. If the process is working you should be able to slow the idle down a bit and have it continue to idle. Again, as slow as you can and have it keep idling. Now adjust the mixture for fastest idle.
Repeat this process until you can't get it to idle any slower or you achieve a suitable idle speed.
Rod
After a lot of fiddling I finally managed to get my YZ-125 to idle, most of the time...
I am still working on the WR-250.
To me, it is really important that the bike idle, at least for a minute, and especially when it is hot. When I am riding really difficult terrain and need to creep over some obstacle, especially down hill, it is a real pain to have the engine die. After you have been riding 60 miles of difficult goat trails the extra effort to start the bike becomes an issue.
If you just ride at the MX track I suppose it wouldn't matter too much, as long as the engine doesn't die mid jump.
To get the engine to idle the first thing you want to do is make sure you don't have any air leaks. This would include crank seals. While you are at it check the reeds and make sure they are in good shape. Minor leaks or minor reed warpage won't bother top end much but it will be hell on the idle.
Next step would be to clean the carburetor and make sure the float level is correct. If the float level is off you may never get a good idle and changing the float level may change the idle characteristics.
Once everything else is proper then it is time to make adjustments on the carburetor. There will be two screws that you are dealing with. One adjusts the idle speed and the other adjusts the mixture.
Start with the bike warmed up to normal operating temperature.
Set the idle speed to whatever it takes to get it to idle. Now adjust the mixture screw to get the fastest idle.
Now adjust the idle speed a bit slower. If the process is working you should be able to slow the idle down a bit and have it continue to idle. Again, as slow as you can and have it keep idling. Now adjust the mixture for fastest idle.
Repeat this process until you can't get it to idle any slower or you achieve a suitable idle speed.
Rod
- Thread starter
- #8
rmc_olderthandirt said:
Yeah, see I agree with you more than any one right now (not saying that any one else is flat out wrong) but deff when I am riding through trails its a pain to have to constantly rev up....its not like I am going to let the bike idle for over 30 seconds to a minute, sometimes you just need enough time to adjust a helmet or something like that....
its not that they are not meant to idle its that at most times there is no point to having it idle. the bike [if tuned properly] should start first or second kick if it dies. and if it doesnt then you need to tune your bike. my cr125 doesnt idle and i ride trails alot and i only find my self in one situation the whole weekend where i wished my bike idled
I think a 2 stroke that idles is a sign of good jetting. Mine idled just fine. I always used the same starting procedure. I would let it idle until the cylinder was warm. I never did any damage to the engine and it idled when I sold it. A bike that doesn't idle usually is just rich and guys (at least the ones I ride with) feel it needs to be "fatter" because they ride harder. Run it how you want it. I liked mine to idle so I could squeeze through the trees without worrying about stalling.
helio lucas
~SPONSOR~
- Jun 20, 2007
- 1,020
- 0
this is a very good question... idle or not??
dual sport are supposed to idle until it run out of gas...
from my point of view mx bikes don´t idle very well. first because most of their carbs don´t have a very efficient idle circuit, second because they have to run very rich in idle circuit to avoid overheating and sizing and third because they don´t need to...
i think all bikes should idle for at least, say, 10-20 secs... the only exception is when competing if you unscrew the idle screw you will get some more engine brake... more like four strokes...
dual sport are supposed to idle until it run out of gas...
from my point of view mx bikes don´t idle very well. first because most of their carbs don´t have a very efficient idle circuit, second because they have to run very rich in idle circuit to avoid overheating and sizing and third because they don´t need to...
i think all bikes should idle for at least, say, 10-20 secs... the only exception is when competing if you unscrew the idle screw you will get some more engine brake... more like four strokes...
Ol'89r
LIFETIME SPONSOR
- Jan 27, 2000
- 6,961
- 45
96CRkid said:
A bike that does not idle can usually be traced to a clogged pilot jet. Will it idle with the choke on? If so, remove the pilot jet and make sure you can see daylight through the little hole in the center of the jet. Also make sure the pilot air passageways are clean in the carb. If your bike is jetted correctly and has the correct size pilot jet it should idle. The factories wouldn't go to all of the trouble of installing an idle circuit if it wasn't meant to idle.
Weather or not you want your bike to idle is a personal preference. That's what the idle adjustment screw is for. I prefer to have my bikes idle and never had any problems making my two-strokes idle.
Idle is one of those funny words that if you say it enough times it completely loses it meaning. :coocoo: :laugh:
stumanarama
Member
- Aug 29, 2007
- 306
- 0
btm1948 said:
The bike, if tuned properly, should probably idle as well. As easy as it is, I do not personally enjoy trying to starting my bike while my friends(with them new fangled four strokes)ride off without me(whats worse is that even if they do stall they all have E-start). So that is why both of my two strokes idle just fine until the tank runs dry. Not to say I ever do that. Its just nice to be able to pull up to a fork in the trail, put her in neutral, decide upon a route, put it in gear and leave. All this of course is merely personal opinion. If you don't mind taking the extra step to start your bike every time you stop, then make sure she starts easily and forget about the idle.
Floridadtz
Member
- Jul 10, 2008
- 2
- 0
NEED idle!
Hi guys. I need my DT175 to idle, because I ride it on the road. It has lights, signals, etc. I can't have it die at every stop sign & red light!
I've owned this bike almost since it was new(1979). It has less than 3000 original miles on it. It has been abused and neglected most of it's life. But it used to idle 20 years ago - been in storage alot since then. Recently I "restored" it; all new paint, tires, parts etc. It looks great now, and runs real nice, but will not idle.
I've had the carb apart, cleaned it real well, checked float level, adjusted it like the book says - still no idle. I did a pressure test on the case, found a small air leak at the maniold, where it meets the head. Fixed that; then it held 6 lbs pressure for over 10 mins! So it is solid now.
I still have the oil injection system, it is working fine.
I was hoping someone with a bike that idles, could send me some close-up pics of their carb, to make sure I have the correct holes plugged (I have a plugged hole on the left side, and an unplugged air vent on the right side).
It makes little difference when I adjust the mixure and/or the idle screws. But like I said, it accelerates and runs great.
I am assuming at this point, that it has to be an air leak somewhere on or near the carb - - so I'm hoping your pics would help. Thanks!!!
Hi guys. I need my DT175 to idle, because I ride it on the road. It has lights, signals, etc. I can't have it die at every stop sign & red light!
I've owned this bike almost since it was new(1979). It has less than 3000 original miles on it. It has been abused and neglected most of it's life. But it used to idle 20 years ago - been in storage alot since then. Recently I "restored" it; all new paint, tires, parts etc. It looks great now, and runs real nice, but will not idle.
I've had the carb apart, cleaned it real well, checked float level, adjusted it like the book says - still no idle. I did a pressure test on the case, found a small air leak at the maniold, where it meets the head. Fixed that; then it held 6 lbs pressure for over 10 mins! So it is solid now.
I still have the oil injection system, it is working fine.
I was hoping someone with a bike that idles, could send me some close-up pics of their carb, to make sure I have the correct holes plugged (I have a plugged hole on the left side, and an unplugged air vent on the right side).
It makes little difference when I adjust the mixure and/or the idle screws. But like I said, it accelerates and runs great.
I am assuming at this point, that it has to be an air leak somewhere on or near the carb - - so I'm hoping your pics would help. Thanks!!!
they all should idle- if they are loading up then there's something wrong plain and simple
start with good oil!
clean air filter
then check the plug, you want a nice tan color ,not a dark oily look
then go from there -i use 40:1,and 32:1 in my air cooled bike,but you have got to use good pre mix oil -- i think klotz is one of the best oils out there
THEN,AND ONLY THEN--- mess with the jets-
fuel ,and oil go through the jets, unless it is oil Injected -
if the plug is wet - it might be a lil big on the main
i highly suggest you try these other things first
start with good oil!
clean air filter
then check the plug, you want a nice tan color ,not a dark oily look
then go from there -i use 40:1,and 32:1 in my air cooled bike,but you have got to use good pre mix oil -- i think klotz is one of the best oils out there
THEN,AND ONLY THEN--- mess with the jets-
fuel ,and oil go through the jets, unless it is oil Injected -
if the plug is wet - it might be a lil big on the main
i highly suggest you try these other things first
Track law clearly stated that a 2 stroke comes off bottom with near to no idle stronger, purely rumor mind you! I have asked before if a dyno will show the engine coming off bottom, as it does in the dirt? I have felt it, others have also. A simple test you can perform yourself. It is a mystery why a 4 stroke is easier to kill in a corner. Here we go again, myself and others have found it better to have the idle cranked up as high as you can ride it on a 4 stroke. Carb design or the torque thing? The bigger the 2 stroke, the harder to get to idle. Bottom line is if you can't get it to idle, you have mechanical issues somewhere. As easy as an airfilter, to an engine overhaul. You need some tools and a manual, and get used to looking at your plug, alot!
- Thread starter
- #21
whenfoxforks-ruled said:
Haha trust me, ive gotten very familiar with a plug ever since i started riding a 2 stroke. Im pretty sure its like Ol'89r is saying, to clean my carb real good. Im good at cleaning them myself.....so i think ill give that a try and get back to yall.
Floridadtz said:
Since it sounds like you have been pretty thorough with the carb, let's look at the simple things. What is the slowest engine speed it will run without stopping when you use the throttle? Can you keep it running by cracking the throttle just a little, or do you have to constantly blip it? If you can keep it running by holding it open at a constant position, is the engine speed too high to be considered an idle? If it is satisfactory, adjust your idle speed to that level.
Floridadtz
Member
- Jul 10, 2008
- 2
- 0
still won't idle
Yeah, I tried all of the above. I put good quality MC oil in the case, $4+/qt. The mxing oil I used cost $9/pt from the Honda dealer. I've gone thru the carbs, made sure the float level was right, and made absolutely sure ALL passages were clear -cleaned em whether they needed it or not, using wire & compressed air. Running a brand new air filter, new plug too. Did the pressure test on the case- good! Removed & inspected the reed valves, all is ok there. The jets were never changed, they are the originals - the bike used to idle with them. Adjusted the throttle cable for minimum slack. Put a new fuel filter on her, and "rebuilt" the petcock.
As far as checking the plug color, do I just try to keep it running, without revving it above idle, then kill it and and check it? I'm assuming riding it, then checking the plug will tell me nothing, since it accelerates and runs great.
It won't run without constant feathering, unless the choke is pulled slightly out. Then, it bogs when accelerating. Sure sounds like the idle jet is clogged right? But it's not, and is making me crazy! :coocoo:
Yeah, I tried all of the above. I put good quality MC oil in the case, $4+/qt. The mxing oil I used cost $9/pt from the Honda dealer. I've gone thru the carbs, made sure the float level was right, and made absolutely sure ALL passages were clear -cleaned em whether they needed it or not, using wire & compressed air. Running a brand new air filter, new plug too. Did the pressure test on the case- good! Removed & inspected the reed valves, all is ok there. The jets were never changed, they are the originals - the bike used to idle with them. Adjusted the throttle cable for minimum slack. Put a new fuel filter on her, and "rebuilt" the petcock.
As far as checking the plug color, do I just try to keep it running, without revving it above idle, then kill it and and check it? I'm assuming riding it, then checking the plug will tell me nothing, since it accelerates and runs great.
It won't run without constant feathering, unless the choke is pulled slightly out. Then, it bogs when accelerating. Sure sounds like the idle jet is clogged right? But it's not, and is making me crazy! :coocoo:
Being it runs better with the choke out, try a larger pilot. Usually how many turns in or out the air screw is tells you which way on the pilot. If you look at the plug while its having issues, it will tell you if it is from not enough gas or too much.
