About Ready To Sell This Thing!

[Brian]

As many of you know, lately I haven't been happy with the way my bike runs. Now, I'm even more unhappy. It pings and knocks, and now, after messing with the air and idle screws(with no good results) it revs itself way, way, way up when running the fuel out of it. I've always done this, eve though some say you shouldn't etc... with no problems before. It used to idle up slightly, then die, but now I have to kill it it idles so high, plus the jetting stuff. I'm getting so fed up with this, I'm about ready to sell it. Just had to vent a little... :( :(

 

[canyncarvr]

Yes, you should (sell it).

Give up on it post haste. Do NOT use this experience to learn anything, just quit. Anything you learn will just benefit you at a later date..maybe on another bike. Who needs that? What a waste of time!!

Well.....you might reconsider.

Listening is a good place to start.

re: '..I've always done that...'

Yeah..well...so? Don't! What do you perceive the benefit to be of running a 2-stroke extremely lean with no lubrication? And then letting it SIT afterwords?

If something bad happens after you've 'messed with' something, the first thing you do is UNdo it! The kdx can change from a turd to sweet with just a bit of turn on the AS. That you've 'messed with' it to no good effect is some indication of the problem. If in fact the bike shows no difference in response to AS adjustment, then something else is wrong. This site can tell you what.

You've proven to yourself how screwed up you can make things with jetting.
Jetting can have just as large a POSITIVE effect on a bike's performance.

 

[Brian]

Originally posted by canyncarvr
If something bad happens after you've 'messed with' something, the first thing you do is UNdo it!

Believe me, if I knew what I've screwed up, I'd fix it, and then even be happy and not worry about he pinging and knocking. I'm open to any suggestions. Are these symptoms of worn reeds?

 

[MassKDX]

I would suggest reverting back to the stock jetting and when your carb is out pull your reed cage and check your reeds. This process takes thirty minutes or less.

A few questions for you Stan.
You bought this bike used correct? Did it make these sounds when you took it for a test drive before you bought the bike? What octane fuel are you using? Did you try CC's suggestion on the oil (filling it up with more oil)? These are just a few questions that need to be answered in order ot help you out properly.

I know my bike makes a slight ping noise and it always has since I bought it. The ping got louder with an after market pipe. My plug chops look good so I am not too worried about the ping I hear. I use the highest octane fuel I can use (93).

 

[Brian]

Thanks for the help guys, I was judt really sick of nothing working, and had to vent. I did buy the bike used, but didn't pay attention to any noises when I bought it, but I'm pretty sure it's always done this. It pings when I rev it up to 1/4 throttle or so, let off, then ping, ping.... The pinging isn't consistent, sometimes it won't do it at all, sometimes it does it alot. I use premium pump gas(not sure what octane, probably 93). Never over-filled the tranny to reduce clutch noise, because, that doesn't bother me, and I'm almost positive this is coming from the cylinder or silencer. The powervalve rattles also. The bike makes a lot of odd noises, but the pinging is the only one that bothers me. Now, I wish I knew why it revs up so high when running the fuel out??? The pinging is starting to bother me less, as I'm learning to accept it, but now, another problem :(

 

[dirt bike dave]

Your float level might be low. Less fuel in bowl = not enough fuel getting to engine = pinging under load and early lean rev when running the bowl dry.

 

[BucKat]

First off,,,,stop running the bike out of fuel as CC sayed.
This causes the engine to run very very lean and as result it will over rev...That's just the way it is...
There will be no lubrication and damage will result very soon.
Don't do it!!

Check the float level as dirt bike dave mentioned.
Go back to the recommended jetting and A/S setting and start over.
Check the timming.
Clean the pipe and change the packing in the silencer.

visit JustKDX.com and Erric Gorr's sites for info on how to do the above..
Most of all KEEP A LOG OF YOUR RESULTS..(notice the capital letters)

Good luck and don't give up...check out a couple of my threads and you'll see your not alone.

Oh-ya......how much????

Joe

 

[MTRIDER]

If you are still having trouble PM me and we can get together and we'll get it runnin right.....but you have to give me your tank :)

 

[agitt73]

i'll give ya 50 bucks for it
if you will ship just kidding
dont give up they are a good bike

 

[Brian]

Thanks again, now just a few questions...

How do you check the float level? What is the proper setting?
I'm at the recommended jetting, but what should the airscrew be at?
The idle screw has no effect on anything? What's with that?
I didn't think the stock silencer(S/A) had any fiberglass packing?
Isn't the timing already set? And this is serious stuff, I don't want to mess with that, it could end up even worse.

I can live with stopping running the gas out, but what worries me is that when I did it before, it didn't idle to the moon, since then I've tinkered, but put all settings back to normal, removed the carb and re-installed to ensure good fitting, and now it does idle too high. I was worried I may have an air leak, but wouldn't that affect idle evrywhere, not just when running the carb dry? I'm all confused :think:

 

[gooby]

ya don't throw in the towel stan u'll get it :) chk that float ht,i run a 155/45 pa 1 1/2-1 3/4 out 40:1 i hate to do that u'll post it blew up with those if u use em but it sounds close to what ur using. stop runnin it out of gas too lol

 

[Brian]

Gooby, you're saying 155/45 is too lean :think:

 

[gooby]

no that's what i run,i'm sayin my luck somethin will happen cause i mentioned it lol.no it runs sweet(mine) r u using a 45 p or a 42? if 42 maybe a 45 would b better if ur lean ?

 

[BucKat]

Check to see that your throttle cable is not bound up somewhere and that there is the proper amount of free play in the throttle.
If the timing has never been tuoched then leave it and don't worry about it.Don't worry about the siliencer as well...I didn't realize it was a stock spark arrester.
follow gooby's advice and get back to us.
Canadian Dave at JustKDX has tips on how to check float level. if you don't have caliper( most of us don't) use the parallel method on CD's site.
Good luck and how much??
Joe

 

[Robcolo]

If you're hearing this "pinging" noise after closing the throttle --that is -- the engine is not under load or acceleration then it is NOT preignition [pinging / detonation] It's most likely piston slap or Kips valve noise. Some of the oem pistons were cracking in the skirt area - just look inside it to see why.
If the air screw has no affect, then your pilot jet is incorrect or pilot circuit is clogged.

 

[kdxtaz]

Float height is 16mm from float bowl mating surface to top of float. Better yet, get a fuel level gauge from the dealer - much more accurate! Like CC said, don't run it out of gas - very bad, though the high revving is normal. I ran out of gas while ridin' once. The thing just took off!! Very scary. :scream: The kill button wouldn't kill it, either. The mixture was so lean it was igniting spontaneously. And hey - If there was any quit in you at all, you woudn't be ridin' dirt! ;)

 

[Brian]

Will check the throttle cable, but why would that have anything to do with it?
The airscrew is affective, just not the idle screw :think: I don't think the pilot is clogged, because I just put in a new 45 last week. I'm pretty sure it's not the KIPS valve, though, because it rattles all the time, not just when letting off the throttle, and the pinging is a different noise than what the powervalve makes. I'll probably tear down the top end soon, and I guess if it's all normal, than I just live with it being a two stroke ;) I'll stop running it out of fuel, but the thing that bothers me is that it didn't used to rev like that before I tinkered with the carb yesterday. I put all settings back to normal( all I messed with was the needle and airscrew/idle screw) and am afraid I have an air leak somewhere? But if I did, wouldn't it idle high all the time, and not just when running it dry? Thanks again for all you're support, like I said, I just had to vent a little ;)

 

[70 marlin]

when I installed jr's new/used IMS tank. I removed the petcock from the old tank and found it completly plugged? might want to take a look down into your fuel tank.

 

[Brian]

Will check out the petcock, although I doubt that would have an effect on either of my problems. In another forum, somebody suggested a new bottom end bearing or rod, and I think that might be the ticket, will have to tear it down and inspect it after the ride this weekend, or would it be harmfull to ride it this way??

 

[Bill Hibbs]

How many turns out is your air screw now?

 

[canyncarvr]

Stan:
A lot of good points in this thread ...don't let them slip by in the profusion.

A couple of interesting points:

1. From Robcolo re: pinging. Yeah. What he said. What you're describing doesn't sound like pinging to me, either. Maybe just good 'ol kawi racket!! yee-haw!!

2. Float level. If you set the floats so they 'just touch' the sprung pin on the needle when the mold lines on the floats are parallel to the carb body, you'll be fine. Adjust by bending the TANG that hits the sprung pin, NOT by bending the floats themselves. DON'T DEPRESS THE SPRUNG PIN TO DETERMINE THE FLOAT LEVEL!! It's easy to do. Don't.

3. Here's the kicker. You said you '..all I messed with was the needle.' I'll bet you didn't get the white nylon cable retainer seated onto the needle retainer nut correctly. Check it! There is a tab on the nylon piece that MUST fit cleanly into the corresponding slot on the needle retainer nut.

4: The 220 oem pistons had problems. The 200 oem pistons are pretty solid.

5. What sort of 'effective' do you expect from the idle screw? (that's the black, angled one..NOT the brass one). It doesn't contact the slide right off the bat, which is to say, if it's out a good bit (exact, 'eh?), a turn or two in OR out isn't going to make a difference in the idle. AND with it NOT CONTACTING THE SLIDE AT ALL, you can STILL have a runaway idle problem.

I would suggest NOT doing anything like a top-end until you get some of this sorted out. You'll be adding insult to injury (yeah..that doesn't fit, but you get the point?)

I'm telling you (cuz I'm old and you should respect your elders;) ) to take the cap off your carb and check that throttle cable retainer..and let me know what you find!!! The nylon retainer MUST sit flat on the nut, and the locating tab MUST fit smoothly into the slot. (repeated for emphasis....again...)

Oh...and quit running your bike out of gas!!;)

 

[Brian]

canyncarvr, I forgot to mention, I took the slide off, and put it back on to ensure the collar is properly seated, and it is. The idle screw has no effect at all, the airscrew does, and is between 1/2 and 1 turn out right now(I think, didn't keep track while making adjustments:uh: )

 

[Bill Hibbs]

Sounds like your pilot jet is a little lean. I'd go one richer and set the air screw about 1 1/2 turns out for starters.

 

[Brian]

Okay, new problem... High idle all the time except when airscrew is all the way in. Can you say 'air leak.' The only problem, I can't fin an air leak. Idle screw still has zero effect, but I think the throttle cable is toast. When I crank the bars left, or compress the forks, there is a very slight increase in idle. I'm almost positive that there's nothing wrong with jetting, because I haven't opened the float bowl, and it used to idle fine before tweaking with the airscrew, but I'm afraid I've torn the boot somewhere(reeds to carb or airbox to carb??) Again, it idles to high unless air screw is all the way in, then even idles high sometimes. What gives? Throtle cable? Air leak?

 

[canyncarvr]

Getting pretty off track here what with numerous issues. Start with: 'Fix what you know is broke!'

If your idle goes up when you turn the bars, there is a cable problem someplace. If it shows up when you turn the bars, who's to say the cable isn't brought up short just sitting there! (hi idle). Check your routing. Put the bike on a stand, move the bars back and forth..look for the bind. Is there slack in the cable? Obviously there has to be. Just as obviously there is NOT enough slack for some reason. You HAVE to find out what that is before going any further.

Changing jets at this point is counterproductive (bad idea).