Oh no,i haven't it from Ducati monster 600----
is a original part From Ducati parts...and for....monsters and ss,600 ,750 or 900.
Is new and sure is for this models...only changing all this parts we are comment.
I only hope my Ducati go..fine..and..enough fast..
sorry my bad english

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.

Hi again,thanks for all are you telling me. Im now in the " taller" (place where the mecanis works) and with the jets as 900 but with the needles original( 600).the bike is allready bas.. The plugs whithe and dry...ist men... Shorts...and we dint kniw what to do...
Only can be the needles ? Changing it for the 900...do you think will be better?
The air is so so short... To compense the short engine in the cylinder...that we dont konw...couse the air is only 1/2 from top
Tell me whatever youll do in this momment please
Thanks again

If you haven't already, try a 40 pilot/slow jet to get rid of that off idle lean spot and now you can go back to needle posn #4 (or even #3). You may need to use posn #4 with pods or a modified airbox and K&N or similar filter. Sometimes oem needle jets wear oval and cause excess fuel consumption, often within low kilometers. Replace the oem needle jets with Factory Pro needle jets, they are more durable.

Factory Pro or Dynojet jet kits solve oem jetted BDST 38 Mikuni carb midrange lean conditions, but with the extra notches, its easy to overdo it seeking more power!
If you have already fixed the problem,

The 900SS jetting has a 42,5 pilot jet and the clip on the needle is on the 4th notch, so with his setup it`s a better starting point than the 750SS jetting.

Cool .