Bike won't rev or pull away :(

[widget2k4]

Just finished a rd250lc and cannot get it to pull away without it bogging down big time, it idles perfect,engine is really quiet and rattle free,it has all new seals in, but in neutral it will bog down and die if you try and rev it quick,if your gentle with it you might get it to rev, but if I give it a quick pull on the choke then off again it will rev faultless for a few minutes? I can also use the choke to pull away then knock it off and the bike will run flawless with loads of power and doesn't hick until I have to stop and pull away again.

It has me stumped now and for days I have messed with it,this is what I have changed with known working parts,
Plugs,cdi,coil,reed valves and inlet rubbers,carbs,needles,jets, I have tried timing,mixture etc but seems to make no difference.
I have checked for air leaks with carb cleaner,

I have just ran out of ideas now and would like to get it running right so I can get it for an mot and up for sale.

Thank you

[flames]

are the float heights set correctly? sounds to me like its not getting enough fuel if it runs better with the choke on.are you running with standard pipes? carbs balanced and all settings set to specs?

[widget2k4]

Float hights are right,carbs balanced all settings correct,standard pipes but have been cut and welded,I presume they have had restrictions removed

[widget2k4]

Fixed changed pilot jets from 20 to 22.5 and it's sweet now