2200 miles, cannot figure out the prob looking for some help.

Took the carb apart again saturday, soaked all non-rubber parts in carb cleaner till monday. Used compressed air can to blow everything out, looked at every hole in the jets and diaphragm with a magnifying glass, put all back together and still runs rough. Cranks right up, purrs at idle then goes downhill from there. fuel/air mix prob somehow. also new plug.
Haven't heard it backfire yet as it has been.
once i get it out of first i can run it thru all gears wide open but the second i use the brakes and then down shift to 2nd or 1st it spits and sputters and dies. same as takeoff in first. a few weeks ago it would run better with a piece of pre-filter over intake but that's not how I want to run it obviously.

its a simple carb, sheesh.

Found a dynojet stage 1 kit for it for $48 is there anything else i can try before spending money. The carb looked perfect today. Looked at fuel line for cracks or leaks, all air intake assembly nice and snug. My battery is new and tests fine. Im frustrated with this as we cant ride as a family.

Thanks for any input you may have.
I guess 00-05 models are the same for most things.

 

Sounds like it may be getting too much air. You sure the rubber boot for intake isnt cracked and your just not seeing it? Reason i ask,is you said once you put a pre filter on it ran better which means you restricted the air flow,(slowed it down). id look over all you intake hoses,boots,ect... whatever there is involved with the intake and see if something is damaged, bent,squashed or something. If a rubber hose is worn out it can collapse when you give it gas which will cut the air flow off also. May check you carb screws also. make sure they are where there supposed to be. The color of the plug will tell you what might be happening too. white,black,tan? not to mention is it gaped correctly?

 

Thanks, i have checked the entire air box. I will start easy by getting a new plug with proper gap again and maybe a gasket where it comes off the engine to the carb.

 

I know this off the wall But have you replaced spark plug and check charging system?