what I did cause no I didn't have a Y piece on hand was move that X you see on the blue pipes back to the red, which has a T piece on it in the pics. then connect the 2 coming from the solenoids to the freed up T piece and used a leftover bit of pipe to connect the T to the X
Please excuse the drawing I have added to help out , blue for solenoids and pink for carbs. Also I haven't looked at the 21 diagram yet no
nsrdownunder dropped in and this is what we/he came up with I think I got it right putting them on .
_________________
NSR250R MC18