I recently purchased a 2006 KLX250S. This bike only has 1300 miles on it. However it had an incredibly hard time starting (especially when cold out). I spent some time reviewing forum remarks and opted to remove the carb, remove the air/idle screw plug and back it out 2.5 turns off the seat. It appeared to be roughly 3/4 turns out from factory. That seemed to help the starting issue but this bike is so anemic now that it will barely get out of its own way and I mean that Literally. I would be afraid to go out on the road as accelerates so slowly. Anyhow I then removed the carb (2) more times and kept backing the air/idle screw in until what I believe was the factory setting. AGAIN this thing is a pig!!! There is no possible way that it came from the factory this slow, I mean my kids xr50 would beat it and Im not kidding. What gives? I had completely dismantled carb and cleaned thoroughly. Any ideas?

 

I don't know...I think in bone stock condition, they're pretty anemic. Until mine had a pipe, Dynojet kit, and airbox opened up a bit, it was very disappointing. After those mods, it felt like a strong running XR250R with an aftermarket pipe and similar mods.

 

Is the needle loose so it's not being pulled up by the engine vacuum? Some passage in the carb plugged? Running right, even stock, it's not as anemic as you describe.

 

Will the bike achieve 70 mph?

Air filter clean?

FRESH fuel?

David

 

Sounds like you keep removing the carb just to adjust the fuel/air screw. If you use one of those little screwdriver bits that are less than an inch long and a hex on one end, usually magneteic, designed to fit into a nut driver handle then you can just put that in there to adjust the carb without removing anything.

You have apparently botched something with your cleaning/disassembling/adjusting of the carb. These bikes are not slow. I just competed in a desert race and was flying past KTMs and other fast bikes with good riders. The KLX can hang with the best of them, especially when you realize that the redline is way way up at 10,000.

Maybe you bent the float tab, didn't seat needle right, or have a leaky diaphragm up top. There's really not much else going on inside the carb.

 

Highbeam, no disrespect to you personally, but I would definitely debate your statement about how a KLX can hang with the best of them. You know how much I love my KLX, but it is not a KTM or other higher strung competition bike. It's weight alone would be a negative compared to most KTM's or other true competition bikes. When you factor in the horsepower deficiency of the KLX to those bikes, it gets worse. Now, it sounds like I'm slamming our beloved KLX, but all I'm really saying is that it's not a true competition bike to go head-to-head with real race bikes. It is, however, a dual sport bike that can be ridden just about anywhere you can ride a real race bike...albeit at a slower pace.

I do not doubt that you could have been smoking some guys on KTM's or other race bikes at your event, but maybe their pilots weren't quite that fast with the machine. There are few absolutes, but I'd bet the same riders on a given KTM and a given KLX could always turn faster times in the woods, in the desert, or just about anywhere...and probably quite a bit faster. I ride with guys on real race bikes out at our riding area quite frequently. The only place I see my KLX being on a more equal footing is when you come upon that loose, gnarly, climb where traction is more important than power. Everywhere else, those KTM's and just about every other race bike can pull away from me unless they screw up.

I do agree with you that the OP probably messed something up while going into the carb during the tweaking sesssion, and he may have trouble until he puts his finger on it.

 

Thanks for all the advice, found the problem. Diaphram on top slide was sucked in partway and obviously not sealing properly. This makes sense why it would not rev or accelerate well. Seems to work fine now however still a slug. depending on the headwind I was able to reach 60 mph into headwind and with tailwind/no wind I hit 75mph. Is this normal? seems like it should be quicker.

 

Yep. Stock, this is normal. I had a slight uphill into the wind one day, and I couldn't even hit 60 indicated...which is only about 55 actual. However, with airbox modifications, a freer-flowing slip-on exhaust, and rejetting, it would hit 70 on that same hill into the same wind. Now that I have a 331 in it, it's much, much better...especially in the lower rpm's where I actually run it (I don't get above 7500 most of the time now).

 

I may have overstated it a bit.

The KLX can hang with a KTM meaning that you can take a KLX and go on a ride and most races with those bikes and keep up just fine. What I did not say is that a KLX is faster than a KTM or that the rider on a KLX will never be limited. Then you need to consider the conditions. The only time that max HP will do you any good is in a straight drag race type situation where wide open throttle is held. That's not off road racing, that's a drag race.

Put it this way, a pro rider can kick my butt (even if I'm riding a KTM) on an XR200. The KLX is good enough that the rider's skill will be what wins the race, not the bike. You can't take this to extremes because of course the KTM race bike is superior on paper and in reality, just not as much as some folks think.

I'm with you though on the superiority of KTMs. I would love a little KTM200 for the races.