KDXRIDER.NET

I need some help guys. When I stop and idle my bike, fuel pours out of a plastic tube under the bike. I inherited the bike about 5 years ago and don't know if it has been modified in any way. I haven't ridden it much until this winter/spring. I don't remember the bike doing this befor. Also whenever I ride on slow trails (very slow with my kids) I foul spark plugs. What is going on? what can I do about it. The dozen or so times I rode the bike befor this winter, it ran fine with no fouled plugs.

Most likely your jetting is rich and is contributing to your plugs fouling. You most likely want to check your float needle in the carb for wear. It should look like a sharp triangle. If its got a ridge running around it then it needs to be replaced. Also check the float height. If its adjusted too high then the bike will tend to pee most anytime.

Float height will also change mixture so do what morie said before you mess with jetting.

How do you adjust the float level?

you bend a little tab that moves the float needle. Read all the "sticky" threads on this site. What you really need is the shop manual. It'll save you aggrevation and much money. Working on these bikes without one will get you broken parts.

Why didn't I think of that? I have the stupid book. Oh well, did the job today. The first try got the float way out of spec the other way. The second try worked well. No peeing. The bike ran well, really well, for about an hour and then started acting up. The idle was surging. I just put it away, and I'll look at it another day. Any suggestion?

surging, meaning the revs rise and fall on their own? that could be too lean jetting, or something else, or an air leak in the intake or crank seals. Air leaks are very dangerous because sometimes they're intermittent and you tend to ignore it, then the resulting lean condition could blow your motor. Since you just changed something, I would suspect that. As in, maybe you dropped the float level too far. Did you observe your fuel level with the adapter/clear tube gizmo you screw into the bottom of the float bowl? If not, how do you know what your float level is set to?

Surging- It revs without touching the throttle. I did not check it with the tool you described. I don't have one. I just measured the float height as described in the book 16mm +/- 2mm from the base to the bottom of the float. I know that is just a starting point and the actual fuel level in the float bowl should be checked but I don't have the adapter. I knew that the float was sticking or set to high an I needed to stop the bike from pissing premix everywhere. Is there another field expediate method for setting the float height? Or, where do I get/make the proper tool? You guys have been a big help so far. I have NO experience with carbs. I can't afford to take it to the dealer, and I prefer to learn and do it myself.

I don't have my manual at work...but .....

A number of things you can find in other threads:

1. The float needle is spring loaded. If you followed the 'old' rule of turning the carby upside down and measuring where the float drops to..that is not right. That method will compress the spring. The correct level is set when the float just touches the pin, but does not compress the pin.

2. Be sure to bend the tang that touches the pin, not the float arms themselves.

3. Be sure the hinge pin is correctly in place when you put the float back on.

4. Take care to not change the float setting when you put the bowl back on. It's not hard to do...bend a float on bowl install I mean.

5. Make sure the carb downstream (reed side) tab is properly indexed to the slot in the carb boot. Having the carb just a tad 'off' will make it pee worse than 'normal'. That said, it IS fairly normal for a KDX to pee. Part of that is a bent/worn out kickstand...if it pees on the stand, that is.

6. Set the float level a tad low..like at least 17mm..maybe 18. You're still in 'spec', but on the low side.

7. You may need to clean the needle seat. That entails a strip of wet-n-dry on a cotton swab used to a burnishing effect on the needle seat.

8. If you can see any mark on the needle where it seals (trys to) to the seat...replace it.


Re: Is there another?

Yes. Set the float mold line parallel to the carb body when the tang (again) just touches the pin.

Re: revs without touching the throttle.

1. You took the carb out to set the level? Check the nylon (white) cable retainer on top of the slide. The tab in the retainer must fit in the slot in the needle holder nut.

2. That being OK, something is either considerably lean or plugged up.

Re: 'and I prefer to learn and do it myself.';

Great!! Have someone else do it and you will likely have to 'repair' it after they have 'fixed' it anyway. If you're going to ride a dirt bike and NOT do your own maintenance..you're in for a world of hurt! LOTS of $$ and LOTS of wasted time hauling to/from the 'shop'..and the aforementioned required repairing on your part.

Good Luck!!

Ask if you need assistance!! Aside for the occasional (VERY seldom actually! ) smart aleckedness from some on this site, someone here can likely answer most any question you have.

**caveat** SR model 220 (non-US) and early 'E' models too? Well...maybe... just possibly....

Thanks canyncarvr,
I'll recheck my work this weekend and get back with the results.
Eddie

all what CC said should get you fixed. Given the bike's history, I would guess the needle valve/seat was the problem in the beginning due to fuel drying up and leaving varnish in there. But thats just a smug little comfy thought in my tiny little mind.

Safety tip: Be very careful with the little 6mm nut inside the carb slide if you get the urge to take that off. Use a good quality 6 point socket, and put anti-seize compound on it before replacing. These are very weak metal, and seize/strip very easily. The slide limits access to it, making removal when it's screwed a total bitch. You need to remove it if you want to adjust the needle position (not the same as the needle valve). I'm only telling you this cuz you're new to it...I would never strip mine and have to order a new one, and then spend an hour slicing a groove in the old one with a piece of hacksaw blade held in a pair of needlenose to get a screw driver into it so I could get it out...

I always put mine in real gently.

OK guys, you're going to love this one. After R&R-ing the Carb 6 times with various adjustments and a couple complete cleanings, I could get the bike to fire up and run for only a few seconds, rev, shut down. Same as before. So I decided to check the petcock. Would you belive, NO GAS! The damn thing was empty. I probably fixed the float level problem the first time. I've been screwing around with this thing off and on for about a month, and all I needed was a tank of gas. I don't mind humiliating myself if someone can learn something from it. Thanks for help. Eddie

That's the wayyyyyy it goes!

Glad to hear you got 'er fixed!

If I had a dollar for every time I did something like that...well, I'd have few bucks! I used to ride a '75 YZ125 in the woods (NOT a great woods bike, but it was what I had) and it would always pee a little so I'd just turn the petcock valve off when I'd stop for a break (don't ask me why I didn't just tear into it and fix it). You can probably imagine how many times I'd "run out of gas" within a few minutes of starting back up again. You'd think I'd learn