[Grundy]

I just purchased a new 06 250X. It is all stock so far but idles extremely rough. I've adjusted the pilot screw all the way out which helped but not enough. It looks like most people are running a #42 slow jet. Would this remedy the rough idle?

[crfsonly]

Your pilot may be partially clogged. Change to a 42 because we're gonna tell you to do that anyways. Set fuel screw to 2 turns out.

[JohnSBA]

Listen to Ken, we all do, and we are happy.

You did mention you purchased new.. I would take it back and make the dealership fix it first. Then, I would buy a JD Jet Kit and install it according to instructions, and do the CCC mod to the airbox. You will not regret it.

[jackreed2005]

I recently had a similar problem with my 250x. I had just installed a JD jet kit and then the bike wouldn't idle right. What I done was remove the fuel screw(don't loose it I did and it cost me) pilot jet and flushed the idle circuit out with carb cleaner and the bike ran perfect after. Good luck it can be frustrating.

[Grundy]

Thanks everybody. I received the JD kit today so I'll install and see what happens.

[Grundy]

I've flushed the carb with cleaner as well as I can without taking it off, installed the JD jet kit with the #42 pilot, opened the top of the air box, removed the screen, drilled the baffle and it still has a rough erratic idle. Other than at idle the thing just rips. Any more ideas?

[[email protected]]

I wish we could hear it Grundy.
These things don't hum along really at idle, but it shouldn't be rising and dropping a lot of rpms either. Doug

[Grundy]

Yeah, I'd like to hear another one of these things run so I could compare. I pulled the bowl off yesterday which took most of the afternoon and sprayed all the orfices with carb cleaner. It still sounds the same. What about the throttle position sensor? Does it have anything to do with the idle? I've had the bike 3 weeks now and I've spent more time wrenching than I did the 10 years I owned an XR 400! Thanks for any ideas anyone may have.

[[email protected]]

I'll bet it's normal and you're just getting used to it. They do have pretty radical cam timing which accounts for the racey sounding idle, and these engines have plenty of mechanical noise, all high performance thumpers do nowadays.
Other than doing the jetting and airbox mods, you'll find that other than oil and filter changes plus air filter maintenance that there is really very little to do but enjoy your bike, you'll be pleasantly surprised.
There are two schools of thought on the valve thing. One is to just ride the bike and ignore them until the bike becomes very hard to start, shim them to spec, order your rebuild parts and the next time the bike is hard to start get your seats re-cut and valves replaced,along with usually a new piston and cam chain.
The other way of thinking is to check them frequently so you can watch for developments, but the fact is that either way gives about the same longevity from what we've seen, there's no monetary or longevity advantage to either way.
For 06 and later 250X's (with their improved valve seats) we usually see about 200 hours or so before rebuild time arrives.
Another thing we see is people with new or low hour bikes reporting dramtically out of spec valve clearances either intake or exhaust. This is invariably someone missing tdc and getting erroneous clearances.
The "Nightmare on Elm St"starts when they shim off those readings.
If you bike starts easily, the clearances are good enough. If not, check the pilot jet for a clog then the clearances.
We haven't seen anybody that I know of with a TPS problem. If your bike otherwise runs great I'd just ride it until you hear another one with the same exhaust set-up you're running for a comparison, because these bikes have proven to be very,very dependable. Doug

[Grundy]

Thanks Doug