:bang: can anyone help me? i've got an 1982 kdx 250 and i can't get it to stay running. it all started when i cleaned the air filter. I just rebuilt the top end and everything went well. Got it running for about two weeks and then this happened. when i let it sit for a day it will run for about 15 to 30 seconds and then bogs out, let it sit for about 10 minutes and try again and it runs for about 5 to 10 seconds and then bogs out and it just gets worse as i go on like this. It seems to get too much fuel cus when i shut the fuel off it runs for a second then stops and the plug is wet. is it jetting, float, needles, air? any comments will be greatly appriciated :worship:
Bike Won't Stay Running
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canyncarvr
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Describe your filter oiling process.
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i cleaned the foam filter with soap and water, rinsed it out, let it dry. when it was dry, i applied pj1 filter oil by spraying on then dabbing the oil off with a rag. I did that on both sides until the oil was tacky then greased the housing where the filter and housing meet and tightened it up.
I had the same problem a few weeks ago and fixed it by simply by putting in a new plug and turning the air screw out (leaner). Be sure to read the first thread on this forum ("Every KDX rider should read this.") If that doesn't work do a WOT chop with fresh plug, clean filter and fresh gas. Make sure you are reading the plug properly i.e. at the base of the ceramic insulator.
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Just another question
When you clean a filter, is the whole bike tuned to having a dirty filter and if so what are the adjustments that you have to make? Does the main jet have to be upgraded. I've got a 155 jet and the needle is the standard needle for the bike. The float seems to be working properly cus I took cover off the float, attached the gas line and it doesn't seem to leak when the float is up. The needle in the main jet sits on one side of the jet, does that affect the performance of the bike?
When you clean a filter, is the whole bike tuned to having a dirty filter and if so what are the adjustments that you have to make? Does the main jet have to be upgraded. I've got a 155 jet and the needle is the standard needle for the bike. The float seems to be working properly cus I took cover off the float, attached the gas line and it doesn't seem to leak when the float is up. The needle in the main jet sits on one side of the jet, does that affect the performance of the bike?
I've been in the same situation as you. Dont tune the bike with a dirty filter. Start with clean filter and with fresh fuel. Also, ditch the soap for filter cleaning, I was doing the same and it doesnt get all the oil out of the filter. One of the DRN members pointed this out ot me, I think it was Canyncarvr(how does he know all this stuff!) I know clean them in a high flash point solvent and all is well.
My bike was fouling plugs out of the blue. I checked the float level, it was way off, and I also found my float needle to be bad. You cant tell if the float level is correct just by pushing the float up. I'm not sure what the level dimension is for your bike, do you have a manual?
My bike was fouling plugs out of the blue. I checked the float level, it was way off, and I also found my float needle to be bad. You cant tell if the float level is correct just by pushing the float up. I'm not sure what the level dimension is for your bike, do you have a manual?
canyncarvr
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RE: I think it was...
.....someone else that said that. Anyway.....
Specifics are a good thing, and remember that a problem well defined is a problem half solved.
You said, 'it all started when i cleaned the air filter.'
If that is so, then that is most likely what the problem is. That's just common sense. Doesn't mean something else didn't crop up, or something else happened in conjunction with the filter cleaning process.
Where did the 'two weeks' fit in? It ran OK after you cleaned the filter for two weeks?
Does '..it runs for about 5 to 10 seconds' mean you are riding it around, or it's sitting there idling?
Choke on or off?
The 'bogs out' part could easily come from lack of fuel, not excess...the wet plug left over from a choke cold start.
re: 'It seems to get too much fuel cus when i shut the fuel off it runs for a second..'
If it's only running for 5-10 seconds, then that statement doesn't really count for anything...I mean, it's going to quit in a few seconds anyway, so having turned off the petcock wouldn't have any recognizeable effect.
In normal circumstances, turning off the petcock would let your bike run (idle) for probably a couple minutes.
Disconnect the fuel line, put the end in a small container, open the petcock and ensure you have a free flow of fuel. See if there is a difference in flow from main to reserve settings (assuming you have a reserve setting).
Heck..see if your problem changes with the petcock set to 'reserve' from 'main'
Unless you are in a dust storm, if the air filter is a question, I'd just take the thing off for a couple minutes. See if that makes a difference.
My point was that an overoiled filter would make you run very rich and could well cause the problem you have.
Jet with a clean filter...and keep it clean. Sure, there will be differences jetting-requirement-wise with a filthy filter...even a just plain dirty one. Unlikely it would get really bad in a single ride..and if it did, well....tough, I guess.
How old is your fuel? If it is (old), change it.
.....someone else that said that. Anyway.....
Specifics are a good thing, and remember that a problem well defined is a problem half solved.
You said, 'it all started when i cleaned the air filter.'
If that is so, then that is most likely what the problem is. That's just common sense. Doesn't mean something else didn't crop up, or something else happened in conjunction with the filter cleaning process.
Where did the 'two weeks' fit in? It ran OK after you cleaned the filter for two weeks?
Does '..it runs for about 5 to 10 seconds' mean you are riding it around, or it's sitting there idling?
Choke on or off?
The 'bogs out' part could easily come from lack of fuel, not excess...the wet plug left over from a choke cold start.
re: 'It seems to get too much fuel cus when i shut the fuel off it runs for a second..'
If it's only running for 5-10 seconds, then that statement doesn't really count for anything...I mean, it's going to quit in a few seconds anyway, so having turned off the petcock wouldn't have any recognizeable effect.
In normal circumstances, turning off the petcock would let your bike run (idle) for probably a couple minutes.
Disconnect the fuel line, put the end in a small container, open the petcock and ensure you have a free flow of fuel. See if there is a difference in flow from main to reserve settings (assuming you have a reserve setting).
Heck..see if your problem changes with the petcock set to 'reserve' from 'main'
Unless you are in a dust storm, if the air filter is a question, I'd just take the thing off for a couple minutes. See if that makes a difference.
My point was that an overoiled filter would make you run very rich and could well cause the problem you have.
Jet with a clean filter...and keep it clean. Sure, there will be differences jetting-requirement-wise with a filthy filter...even a just plain dirty one. Unlikely it would get really bad in a single ride..and if it did, well....tough, I guess.
How old is your fuel? If it is (old), change it.
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in regards to canyncarvr. I cleaned the filter and it started to run like this or not run like this so yah it ran well with a dity filter and i mean dirty. I dont even know how any air got through this thing. The bike would not give me a chance to ride it. With the choke on to begin I would get it started then turn off the choke and keep the throtle going. A fair amount of smoke would come out of the exaust. Then when it seems that it will stay running it just starts to rev down and no matter what i do (open throtle, half throtle or at idle) and I'm not just holding it there I'm reving it so to speak then it dies. The petcock is working properly, I've already tried to see if there wasn't any fuel coming out but there is. I'll try to see if the reserve changes anything. The fuel is only one week old
Thanks for all your support!
Thanks for all your support!
canyncarvr
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Is it blubbering (4-stroking) when it is running?
What happens if just before it starts to die you put the choke back on? Does it die quicker than it would if you left it alone?
Yes, Mr. Who..you are illegal and shall be banished for three days!! :ohmy:
Does the throttle 'work' while it IS running? Does the engine go zoom-zoom?
What is your current jetset, anyway?
And, Mr. Whorton, is what he has basically correct?
Is this one of the models of kdx that historically has had sparky problems? Seems some of the older models are good at losing exciter coils...and spark boxes, too.
Mr. Whorton would know that, too. Well, maybe he's mostly a 200-kinda guy.
Too bad he's been banished. :(
Where's Dirtbikedave (besides in the blue)?
What happens if just before it starts to die you put the choke back on? Does it die quicker than it would if you left it alone?
Yes, Mr. Who..you are illegal and shall be banished for three days!! :ohmy:
Does the throttle 'work' while it IS running? Does the engine go zoom-zoom?
What is your current jetset, anyway?
And, Mr. Whorton, is what he has basically correct?
Is this one of the models of kdx that historically has had sparky problems? Seems some of the older models are good at losing exciter coils...and spark boxes, too.
Mr. Whorton would know that, too. Well, maybe he's mostly a 200-kinda guy.
Too bad he's been banished. :(
Where's Dirtbikedave (besides in the blue)?
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canyncarvr
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I wondered about the 'wiping' part. Generally, a sprayed on oil needs to be worked into the filter by squishing/sqeezing it with your hands.
Takes a good lot of oil from a spray-can to get the thing soaking wet, too. Still, odd that you would 'wipe' it.
If he tries running the bike without the filter (only for a minute or two in a relatively clean environment) he will know if his problem is filter related or not.
He hasn't said one way or the other on that...........
Takes a good lot of oil from a spray-can to get the thing soaking wet, too. Still, odd that you would 'wipe' it.
If he tries running the bike without the filter (only for a minute or two in a relatively clean environment) he will know if his problem is filter related or not.
He hasn't said one way or the other on that...........
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Just got back from camping
well I didn't go camping with my bike but it was fun anyway.
Well I finally got the bike to stay running without the air filter on or the whole assembly for that matter. The carb sprays out gas out of the two air holes in the back of the carb, I don't know if that's a problem or not. Anyhow as soon as you throtle the bike it chokes out but does stay running if I just leave it alone but who wants to do that? I was thinking of getting all new jets and needles for the carb........Is this the proper procedure to take? The pilot needle looks to be o.k. the main jet is a 155 but somehow there seems to be too much gas getting into the cylinder. The gas is dripping out of the exaust not too bad but it still is! :ugg: I am at my wits end i just want to get it going soes I can ride again :aj:
Once again this site is great and I appreciate all the help you guys give. Any :clue: to whats wrong don't be afraid to give your two cents. Thanks again
well I didn't go camping with my bike but it was fun anyway.
Well I finally got the bike to stay running without the air filter on or the whole assembly for that matter. The carb sprays out gas out of the two air holes in the back of the carb, I don't know if that's a problem or not. Anyhow as soon as you throtle the bike it chokes out but does stay running if I just leave it alone but who wants to do that? I was thinking of getting all new jets and needles for the carb........Is this the proper procedure to take? The pilot needle looks to be o.k. the main jet is a 155 but somehow there seems to be too much gas getting into the cylinder. The gas is dripping out of the exaust not too bad but it still is! :ugg: I am at my wits end i just want to get it going soes I can ride again :aj:
Once again this site is great and I appreciate all the help you guys give. Any :clue: to whats wrong don't be afraid to give your two cents. Thanks again
canyncarvr
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re: '..is this the proper procedure...'
I wouldn't think so.
If you have fuel coming out of the low speed and air correction jets (the holes I understand you are referring to), that is not correct. Those are air entry points, not fuel exit points.
I don't recall.. has the float level been verified and has the float needle been checked (does it stop fuel from entering the carb when the float is raised)?
...kinda like Hunter1 said last week?
I wouldn't think so.
If you have fuel coming out of the low speed and air correction jets (the holes I understand you are referring to), that is not correct. Those are air entry points, not fuel exit points.
I don't recall.. has the float level been verified and has the float needle been checked (does it stop fuel from entering the carb when the float is raised)?
...kinda like Hunter1 said last week?
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I've had the float set to one side (meaning slightly bent up) and I've also had the set to the other side (meaning slightly bent down) and i've also had the float in the middle but nothing seems to change the performance of the bike. There's always gas flow to the carb and it definitly does not leak. There is only so much you can do with the carb out of the bike. I've blown in the gas intake, moved the float up and down and it seals completely when the float is up, I've also put gas through it and it stops the gas flow when the float is up, is the float extremely sensitive to where it sits or do you have a little room to play with it? Does the main jet need to be a little smaller or the the main needle need to be a little longer so the flow of gas into the cylinder is a little less than it is?
canyncarvr
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The floats should be the same. There should not be a difference in float height from one side to the other. The float level is set by manipulating (bending) the tang that activates the float needle, not by bending the float arm(s).
Set the two floats the same, set the level to spec or maybe a bit (1mm) lower (helps stop carb peeing).
No, it's not extremely sensitive. You can have it set +/- a mm or two with no huge problems. Of course the overall air/fuel mixture will vary based on the fuel level.
If the carb, '..sprays out gas out of the two air holes in the back of the carb,' that needs to be resolved.
re: 'I don't know if that's a problem or not.'
Yes, it is.
With talk of bending (obviously) the float arms...and independently at that, coupled with fuel 'spraying' out vent/air holes I'd make a WAG that that issue needs to be resolved......correctly.
CJ: The air screw is brass. The idle screw is nylon/plastic. It's unlikely that you have 'one screw' (adjustment) in your carb. Attached is a PWK pic with arrows, names and everything. Note: This is NOT an oem PWK..it is an airstryker; the air screw is one of Ron's (RB-Designs) finger adjustable pieces, but the location of the same type screws is identical on the oem kdx pwk (what I presume you have).
**edit**
It appears the JPEG compression pretty much hosed the text on the pic...but you get the picture? ;)
**edit-2**
Reloaded...it's still goofy (dodgy even)..but easily readable.
Set the two floats the same, set the level to spec or maybe a bit (1mm) lower (helps stop carb peeing).
No, it's not extremely sensitive. You can have it set +/- a mm or two with no huge problems. Of course the overall air/fuel mixture will vary based on the fuel level.
If the carb, '..sprays out gas out of the two air holes in the back of the carb,' that needs to be resolved.
re: 'I don't know if that's a problem or not.'
Yes, it is.
With talk of bending (obviously) the float arms...and independently at that, coupled with fuel 'spraying' out vent/air holes I'd make a WAG that that issue needs to be resolved......correctly.
CJ: The air screw is brass. The idle screw is nylon/plastic. It's unlikely that you have 'one screw' (adjustment) in your carb. Attached is a PWK pic with arrows, names and everything. Note: This is NOT an oem PWK..it is an airstryker; the air screw is one of Ron's (RB-Designs) finger adjustable pieces, but the location of the same type screws is identical on the oem kdx pwk (what I presume you have).
**edit**
It appears the JPEG compression pretty much hosed the text on the pic...but you get the picture? ;)
**edit-2**
Reloaded...it's still goofy (dodgy even)..but easily readable.
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I'll have to appoligise, I didn't bend either side, what i ment was that i bent the tang up and down i just couldn't remember the name of it. what are the steps you take to resolve the gas spraying out fo the vent holes? where do i start? I've had that thing apart a half dozen times at least and i've used a half can of carb cleaner, and used an air hose on it, so it's clean. how do you restict the flow of gas from the float chamber to the cylinder? I truely believe that i am getting too much fuel. I've always hated working on carbs but i am always willing to learn just not sure on the angles to take.
CJS1: The throttle stop screw or idle screw is fairly big and can be adjusted with your fingers it's made that way. The air screw i am talking about is on the other side of the carb and can be adjusted with a flat head screwdriver.
CJS1: The throttle stop screw or idle screw is fairly big and can be adjusted with your fingers it's made that way. The air screw i am talking about is on the other side of the carb and can be adjusted with a flat head screwdriver.
KAY DEE EXER
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Now your talkin' the lingo... :rotfl: Just watch out for the 'bodgy' ones.canyncarvr said:
canyncarvr
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I just missed the lingo...when you said 'one side' and 'the other' and 'center'...I was thinking literally of 'sides'.
Jets 'restrict' the flow of gas from the float chamber to the cylinder. Fuel is pushed into the incoming airstream by way of pressure differentials between the inside of the carb and atmospheric pressures (via the venturi effect). That's what the jets do. They are gauged (by different sizing) to deliver the correct amount of fuel based on the previously listed pressure changes.
Besides changing the float levels, what else did you do in the carb? You didn't happen to maybe forget to put the pilot jet back in? ;)
CJ: Keep in mind that the bike being discussed is a 250. The screws in the 200/220 are positioned as indicated in the pic previously attached.
I didn't know that the idle/air screws were on opposite sides of the 250 carb.
Maybe I'm just missing the lingo on that one, too. ;)
Jets 'restrict' the flow of gas from the float chamber to the cylinder. Fuel is pushed into the incoming airstream by way of pressure differentials between the inside of the carb and atmospheric pressures (via the venturi effect). That's what the jets do. They are gauged (by different sizing) to deliver the correct amount of fuel based on the previously listed pressure changes.
Besides changing the float levels, what else did you do in the carb? You didn't happen to maybe forget to put the pilot jet back in? ;)
CJ: Keep in mind that the bike being discussed is a 250. The screws in the 200/220 are positioned as indicated in the pic previously attached.
I didn't know that the idle/air screws were on opposite sides of the 250 carb.
Maybe I'm just missing the lingo on that one, too. ;)
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- #24
no, this time i really mean the other side no special lingo here. the only major thing i did to the carb is cleaned it and fooled around with the main jet needle (tried all 5 positions). It seemed to perform (perform meaning: run better at idle and only idle) at the top position on the needle so the needle is all the way down which keeps bringing me to the thought that there is too much fuel.
canyncarvr
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I've seen this is a couple other carbs..something you might check....
Seems a safe assumption that something is wrong with the carb if its blowing fuel out the air intakes/jets in the intake bell.
When the main is put back in, I've seen a couple of folks dislodge the needle jet (that the needle moves in and out of). They both tightened the main against the edge of the carb body vs: fully inside the needle jet. Once it fell off that shoulder there was a whole lot of slopping around happening...the engines didn't run for squat. WAY too rich because the main was not sealed inside the needle jet, the carb was pulling fuel from all sorts of places is was not supposed to.
Your mention of disliking carbs (sorry..) gives me pause. Maybe you rushed something, or missed something critical......like unseating the needle jet?
Is this a Keihin, even? Like I said, I don't know what's on the 250s. An '82 might have a Mikuni..and that's the carb that has an easily moved/dislodged needle jet.
Is the jet block at all loose? Take the fuel bowl off (again) maybe check that float level again...and make sure the main is not loose to the touch.
Sorry...it's all guessing on my part. Something obviously is wrong (there's genius for 'ya!), but I don't know what.
Seems a safe assumption that something is wrong with the carb if its blowing fuel out the air intakes/jets in the intake bell.
When the main is put back in, I've seen a couple of folks dislodge the needle jet (that the needle moves in and out of). They both tightened the main against the edge of the carb body vs: fully inside the needle jet. Once it fell off that shoulder there was a whole lot of slopping around happening...the engines didn't run for squat. WAY too rich because the main was not sealed inside the needle jet, the carb was pulling fuel from all sorts of places is was not supposed to.
Your mention of disliking carbs (sorry..) gives me pause. Maybe you rushed something, or missed something critical......like unseating the needle jet?
Is this a Keihin, even? Like I said, I don't know what's on the 250s. An '82 might have a Mikuni..and that's the carb that has an easily moved/dislodged needle jet.
Is the jet block at all loose? Take the fuel bowl off (again) maybe check that float level again...and make sure the main is not loose to the touch.
Sorry...it's all guessing on my part. Something obviously is wrong (there's genius for 'ya!), but I don't know what.
