Bike will idle but won't accept any throttle

[SLaP]

Thanks again for all the help guys. Aside from measuring the float level I've done everything you have mentioned. The airfield and box looked ok, I blew it out with some compressed air just to be sure. I put the pilot screw back to factory recommendation as per my service manual and ran some fresh gas through it. It started up ok but kept stalling when I gave it throttle. I delicately adjusted the pilot screw by ear (don't have access to a tach), and it stopped stalling when I reved i, but was backfiring a littlet. Havn't had time to put everything back on (mount the tank and seats) but when I do I'll take her for a spin and let you guys know how it worked out. Thanks again for all the help.

Just to be sure...
You cleaned the little holes in the jets?
Also, as spiider suggested, did you clean the screen on the petcock?

[cbcanada]

Drain the gas, drop the floatbowl (rebel 250 is a single?) off the carb and pull the jets out and give it a good cleaning. Sounds like a clogged main jet.

Probably bad gas and particulate matter in the gastank.

Allan

Agree with this

[Spiider]

Popping or backfiring at idle is probably a symptom of it being lean. If your airscrew is on the airbox side close it a bit.
What you can do is warm up the bike, set it to a fast idle, and adjust the airscrew to the max rpm (by ear in your case).
Once it is adjusted for max rpm...that's it for the airscrew.

Also, it won't be the main jet...the main is responsible for 1/2-full throttle more than anything else.
The pilot/slow jet is responsible for the idle to 1/4 throttle....then the needle from 1/4 to 1/2 or so...then the main take it to redline.
(They all overlap a tad.)

[SLaP]

^ +1

See the video below, this guy explains carburetor operation and the adjustment process very well.

How to adjust the jets on motorcycle carburetors
http://www.youtube.com/watch?v=y836ZPjvoMI