Hello, just took delivery of a 2009 klx250s on thurs. It was trucker to me, brand new, before i paid for it, i fired it up with the choke pulled out, started no prob. idled about 2-2.5 rpm's. after 4-5 mins of running with choke out, iI pushed choke in and it would die, the bike shop guy who delivered it said the idle needed adjusting, so, i started it ,pushed choke in and used throttle to keep it running while he adjust idle, worked fine that night, started next day with choke pulled out and the thing idled at about 4-5 rpm and the pipe by exhst flange was glowing red in very short order, fan also came on, i killed it then went to keeping it running with the throttle and agin adjusted the idle back down, this cant be right???

 

Something isn't right. These bikes are kinda fussy in stock form but not nearly as bad as you've described. Idling at 4-5 grand will heat that pipe up quickly. Use the choke as a throttle. You can pull it out as much as you need to keep the bike running and warm it up without clicking the choke all the way out. I wouldn't let the bike idle at 4-5 grand. Good luck.

Mike

 

could it be super lean jetting? don't know just a thought, what jet is in it?

 

just get it jetted, stock there jetted way to lean anyways.

 

I'm a little fuzzy on this, but I thought I recalled if you still have the air injection system connected, any extra fuel...like from the choke...will get that second combustion in the head pipe going pretty hot and blue a chromed pipe or cause a pipe like ours to glow. And yes...an extremely lean condition can cause the same thing. If you're sitting there with the choke on, however, this usually isn't a lean issue.

That said, your inconsistent idle problem sounds like something else. However, reading your description is a bit confusing. Is this a brand new bike? I'm taking that it is. Your first startup could indeed have been an idle issue and was corrected by the mechanic. I would suggest, however, that you not run the bike for 4-5 minutes on the choke. That can foul a plug or often just quite running from excess fuel...that can also contribute to the hot head pipe if you still have the fresh air injection hooked up. Get off the choke as soon as you can achieve an idle...or at least turn up the idle **** a tiny bit to let it warm up after turning off the choke...not an extremely fast idle, however.j

Now, on your second startup where you mention the high idle on choke, many bikes depending on the jetting can get a very fast idle going on the choke. In fact on some of them you have to feed the choke **** back in a bit and hold it for a few seconds so the engine isn't screaming. You state "in very short order" that the exhaust glowed and the fan came on. If you're doing the 4-5 minute warmup again with the choke on, that's not good. You should try to get off the choke as soon as possible. I'm a little surprised the fan came on, as these bikes are notorious for the temps staying low enough for the fan to hardly ever come on.

I don't know...internet diagnostics can be difficult without being there to see and hear the problem firsthand.

 

The fuel/ air screw may not be adjusted properly either. When mine was new this screw had to be turned out in order for the bike to start properly.

As has been said, the bikes are very lean from factory and really benefit from being re-jetted. With the choke on, mine will also rev up to around 4-4.5 rpms, but I take it off the choke after about 20 seconds of running. It will then idle normally while it warms up further.
As punk said, I'd get it jetted ASAP.

If your worried about warranty issues then I'd try adjusting the fuel/air screw. You'll have to remove the plug covering the screw first.

Good luck.

 

Sounds like the rpm idle needs to be adjusted. Idle should be set at 1,300 rpms when fully warmed up. I have mine set to 1,500 rpms since its easier to set that way. For the new digital clusters with the bar rpm gauge, you are going to need a reference for each bar. With the choke out on start up, the engine should quickly rev up to 3,500 rpms to maybe 4k rpms. But no higher.

 

Is it running on 09 gas? I would make sure you have good new gas first thing. Then work on the jetting.