1993 xj600 sputtering while cruising between 4k and 7k rpm

[Xjkf35]

Hi there i have a 1993 Yamaha xj600 seca 2. It is mostly stock besides having a delkavik 4 to 1 exhaust and a delkavik muffler. The carbs have 105 main jet and im not quite sure about the idle but i think it has a 17.5 or 17 idle jet, i think... either way when i start riding in the morning and the engine is colder it seems to run fine, but once the engine seems to come up to operating temp it spitters realy hard between 4 and 6.8k rpm ehen holding constant throttle. If i then give it a little bit of throttle input it falls on its face for a second and i give it more it cleans up and pulls like a champ....if i pull wide open thru each gear it makes plenty of power. And makes power all the way up to 10k....it seems to be running rich or at least it did....i turned the fuel screws out to 1.5 turns out from all the way in.....if someone can shed aome light pleese help