Thanks for the input. My next step is going to be to do the float height check.

 

Please...don't check the static height measurement of your float. Check the actual fuel level your carb is really operating with by using a clear tube...like a battery vent tube, chainsaw fuel line, etc. This type of clear tubing is readily available. You don't have to have that special tool that Kawasaki shows in the manual. You have to have your carb off for either of these measurements, so why not do the best one. You'll have your tank off, so you have an available fuel source with an on/off tap. Get a longer piece of fuel hose from an auto parts or motorcycle shop to reach your carb from the tank. Set the carb up in something...I use a vise...that allows you to insure the carb is flat and level. Put the tank on something that allows you to have the tank higher for gravity flow of your fuel. Attach that piece of clear line to the bottom drain nipple of your carb. With the tank fuel on, open that drain stop screw at the drain nipple. Let some fuel flow through and then hold that clear line up against the carb body. Make sure you don't have a kink or closure of that clear line. Shake the clear line a bit to insure you get all air bubbles out of the line. Hold the clear line steady, and what you're seeing is the actual fuel level inside your carb. If it fits within the recommended factory amount, you're good. If not, make the necessary adjustment by tiny bends of the float tang where it contacts the needle. This method insures your fuel level is exactly where it's supposed to be.

Why not the static float height measurement? If that float isn't 100% in its buoyancy value...how well an object floats in liquid...it will yield a different fuel level. There is also a small amount of "stiction" in the float hinge, the float pin, the needle-and-seat, etc. that can influence the static height measurement of the float, yielding a slightly different actual fuel level once fuel saturates those parts. Bottom line is that the clear tube method guarantees what the true fuel level is in your carb.

 

I have a 40 Pilot on mine, with a 331 big bore. I went up from the stock 35 in order to quieten a decel pop, which it helped. However, the 40 is too big, as I found an exhaust leak that I believe is causing the pop (the pop worsened as the leak increased in size). I'll be going back to 35 next time I take the carb off. I run a DJ132 Main jet.

I almost always get at least 50 mpg, sometimes more if I'm on powerline-type roads instead of single-track.

Yours was running rich...no doubt about it!

 

Ok, so here goes my float test. Let me know if I did it right or not. I tried it a couple times and kept getting the results in the 1st picture below. I only was getting fuel in the clear line to the bottom of the float bowl. I knew there was no way that was correct and had to think about what I was doing and what might be wrong. If you look closely at the picture you can see air between drain nipple and the bend in the clear hose. I didn't think that was right and flicked the clear hose with my finger some and shock it back and forth and the fuel rose to the point in the second picture where no air is visibl in the line. If I did this float test correctly then it appears my results show the float is spot on. Correct me if I am wrong or did something wrong here.

 

Great work, Landon. Yes, that's the way you do it, and it looks like your fuel level is spot on. So unfortunately you still don't have your rich condition figured out, but you know it's not the fuel level, so one issue is eliminated.

 

I am going to move on to focus on the jetting itself. First I want to pull the needle and make sure the clip was installed on the second from the top and not second from the bottom. If the clip is in the right slot, should I mess with it? Up of down? I think I am going to put the #35 pilot jet back in. I also ordered a new 118, 120, and 122 main jets. I think I am going to drop it down to a 122 while in there.

New air filter is on the way and I picked up a new plug today. So I will be able to eliminate a dirty filter once I get it back together and see how it runs.

 

Looks like your on the right path man,

I think the stock pilot jet is the ticket.

On the needle position, just start playing with it one adjustment at a time. You can adjust the needle position without removing the carb. just pull the seat and tank and then you can access the top cover of the carb. It takes about 15 minutes to adjust the needle.

Ride the bike for a good long 15-20 minutes and note its characteristics, then adjust the needle up or down. Then go ride it again. Trust me, you will notice the differences. Seems like the 3rd clip is the sweet spot on most of our bikes, but some like the 2nd clip and some run better on the 4th clip.

 

Solid advice above, but be careful with those clip positions. Landon's got the Keihin N1TC needle, not a dynojet needle.

 

Landon-I'm not familiar with this particular bike (yet) but just wanted to offer some discussion concerning your problem. Your thread is really great and informative, but I think you'd rather be riding than offering a seminar on carb maintenance! Hang in there, it's bound to be simple (my vote is stock pilot). I've done a lot of street bike mods in the 40 years of riding, and it seems like your air box is still mostly in tact. Pilot should not need the change. I think your main and needle drilling should be more than enough to compensate for the increase in air flow.
Does the KX snorkel provide a bigger opening for the air box or is it in a different location than the stock snorkel? It seems like that is a popular mod done here (and on a lot of street bikes) but in some cases you may not be directing the air to the right spot. Judging by your photos of the UNI filter and spark plug, it almost looks like the filter is pluging with oil or fuel. To me it indicates lack of air. Is there fuel or oil in the oil box?
You may want to try a K&N OE size filter instead of the UNI. Just a better product IMO. UNI's strike me as lawn mower filters and react the same way to dirt.
If your latest effort doesn't help, I'd go back to stock jets, air box and a K&N filter. 2010 Kawasaki KLX250TAF (KLX250S) Parts, 2010 Kawasaki KLX250TAF (KLX250S) OEM Parts - BikeBandit.com check there for jet sizes. Maybe even trow the stock silencer back on and start over. I always found that silencer/air filter mods did let the bike breathe and rev better, but produced very little performance increase on a dyno. At least then you can ride more and wrench less. The stage one stuff (like this) should be basic with a stock box, high flow filter and moderate jetting changes undo what emissions trolls have wrought. Once you mod the air box, you may as well just get rid of it and go big bore as well. Gains are measured in $$$ at that point. Then at least the carbs are easier to get off the bike. Jetting is like suspension, Should only have to set it up once. I give you credit for catching the issue and not just trashing your bike. Alot of guys build so much stuff on an under powered bike they can't tell what's happening. Best of luck to you and keep us updated on your efforts!

 

My air box is still intact. The only thing I did was switch out the stock snorkle for the KX snorkle, which by my guess lets 1.5 times as much air to the filter as the stock. The filter I posted is not a Uni, its either a No toil or OEM. Since nothing else on the bike has been modded ever, I am betting on OEM.

At this point with my work schedule I won't be wrenching on the bike anymore till next Thursday. Once I get back at it I think my first step is going to be pull the head cover and check the valve clearance. If one of them is out of wack for some reason any jetting I do may not help. So I want to check them before I continue. Then I will pull the N1TC needle and confirm the clip is in the correct slot 2. Then I am going to put a #35 (stock) pilot back in and drop the main jet from the 125 to 122. Install new air filter and plug, reassemble bike and take it for a spin and see how she runs and performs.