Hey guys. I just installed HMF slip on, Uni filter, KDX200 snorkel, Kouba fuel mixture screw and Dynojet kit 2152.
I used #128 main jet, spring, and needle in the 3rd groove, with 2 washers on top of it (towards spring stop). Fuel/air mixture screw is 3 turns out.
Bike runs and idles great. On deceleration pops a little bit, but not too much and not very loud, so i would say it is ok.
After driving it for few minutes something happens and it dies. It would start as soon as I hit starter button, but as soon as i touch throttle dies again. If i put choke on, it dies as well. So if twist throttle even a little bit, it dies.
I checked to make sure fuel is on, tank is not empty.
First time it happened I thought something got in the carb. I took it all apart, blew out all the jets with carb cleaner (took the diaphragm and all the rubber parts out) put it all together, made sure diaphragm is ok, air filter is on, an no dirt is being sucked in.
Started, ran, drove it around a little longer then last time, ran great. Same thing. All over sudden, out of nowhere dies every time I twist throttle. Wasn't even a slow process, like when you run out of gas.
Any suggestion will be appreciated.
Could there be a problem with Dynojet kit 2152 needle?

 

After you ride it for a while, then it dies on on you.
If you let it sit, say for 15min, does it then run OK again for a little while?

After it dies if you open the gas cap does it start running again?

To me it kind of sounds like the carb runs empty of gas.

After the bike starts dying on you, immediately reach down and open the float bowl drain screw. Do you get gas flowing out? keeps running as long as you keep the drain screw open?

If not, you might have pinched the fuel tank vent hose somehow.
After a while the running motor pulls a vacuum into the tank and fuel stops flowing.

--
Mikko

 

I thought of that. I opened tank -- same thing. Opened drain screw -- there was gas there, after closed -- still doesn't run. Starts and idles though. Let is sit for almost 1/2 hr, starts, but dies when touch throttle.

UPDATE:
Took the top of the carb off. Took the spring holder out, put it back together. Fixed the problem. But I am sure once i ride it some more it will do the same thing.
Does that mean my slide is getting stuck? If yes, why? My diaphragm is not pinched, or ripped.
Could it be because of vibration the spring holder covers the hole in the slide?
I have 2 washers between e-clip and the spring holder, should i put 3 or do the washers go between e-clip and the slide?

 

It's not that then....

When the engine is stone cold, does is start better with or with out choke?

3 Turns is a lot on the pilot screw (i know nothing of these KLX's but have paid my dues dorking with other bikes....) are you sure it's not running really rich?
After engine warms up it gets too rich and dies right off-idle??

Any better or worse if you close the screw to 2 turns open?

--
Mikko

 

Tried with 2 1/2 turns out, same problem. See update in previous reply.

 

It would be tempting to say you must have put something together the wrong way in the carburetor. But the fact that it first runs fine and then refuses to take any throttle at all makes is more elusive.

If you simply put the stock needle back in does it then run fine?

--
Mikko

 

Using the old axiom that you go back to the last thing you did when a new problem arises, it sounds like it's something you did in the carb. The muffler and other mods shouldn't bring on the symptoms you describe...but the pinched fuel line was worth a look on reassembly. It sure sounds like a fuel delivery problem.

 

I know exactly what your problem is,,
the slide is hung in the UP position.
The spring that comes with the kit is too weak.
take off your airfilter boot and you will see the slide stuck up.
I garrrr onnnnn teeeee.

 

Well, problem is definitely between slide, needle and spring. Needle and spring are new. But other people ran these on the same bike and they were fine. One thing i am not sure about is what to do with the washers. Dynojet shows 2 washers between e-clip and the spring holder. Not sure what that accomplishes.
Possibility is that slide gets stuck? Not sure why. spring slide and spring are very simple, so i am not sure where i could have messed up. I know I am not pinching the diaphragm.
Have not tried stock needle (which would defeat the purpose of the mods).

 

Follow the directions, look at the picture of how the washers are oriented above the needle clip & holder.

Read the trouble shooting guide. #9 third suggestion. Popping means lean and open the fuel screw a half a turn. But your already out 3 turns, throw in a bigger pilot jet. Get the kouba screw to dial it in w/o the tiny screwdriver and getting at it with a hot motor (exactly when it should be adjusted).

Just another klx owners suggestion....ymmv