[DuckWest]

I have recently bought a 1999 honda xr400r off my neighbor and have managed to get it running. The problem I am having is that the bike will only idle/keep running in low RPMs when the choke is fully on but it will only rev out when the choke is off. If it is idling and I try to adjust the choke even a tiny bit it will die. I can turn the choke off while riding and it will run fine until the rpms get low when it will die.
I have cleaned the carburetor out (using carb cleaner and compressed air on all jets and ports) twice thinking that I might have not have cleaned the pilot properly the first time. I have returned the mixture screw to stock and nether of these helped this issue.

Any help would be greatly appreciated. Thanks.

 

[toddlywayne]

Like everything else,, gas is not what it used to be, it will go bad in less than one year, unless you add fuel treatment, I would clean tank and do a carb job because it is probably all gummed up inside

 

[Easy Rider]

Does it have a stock air filter and pipes ?
Put some Berrymans B12 Chemtool in the gas and do some "test runs" over a couple of days.
Any chance that the idle setting is just too low ?