Your english is much better then my spanish
I changed the pictures, now you should find all jets.
You are right about the needles. The first number is the length (5 = 50-59,9mm, 6 = 60-69,9mm etc.), the letter is the angle/taper (A = 15 min. B = 30 min. C = 45 min. D = 1° E = 1°-15 min. etc), if there`s a second or third letter the needle has two or three angles. The last digits are the serial number which is sometimes followed by the outer diameter of the cylindrical part.
Needle jet and jet needle control the air-fuel mixture between 1/4 and 3/4 throttle opening (the transition from pilot to main jet), so they do have major impact and you should change them.
I just checked the incomplete Mikuni I`m keeping for spare parts and I do have the 5C19 needles and Y-2 needle jets. If you want them just pm me your address and I`ll put them in an envelope and send them off to Spain.
