Jet needles for blaster, banshee, mikuni vm series #5

[deeeebeeeeee]

Here is a place to out pics and specs of various needles, for mikuni carbs, particularly the 5 series used on the vm26ss, vm28-606 etc. IIRC #5 series needles fit the vm series from 24mm or 26mm right on up to 32m or34mm, as well as tm series of similar throat size. If no one chimes in with a for sure, I will look it up later.
The first number indicates length 5 series needles are typically between 50 and 59.99mm in total length. The letter or letters indicates taper or tapers the higher the letter the steeper the taper (which leads to a richer setting). For two letters the first is the taper closest to the clip, the second is the bottom of the needle

Name, total length, length taper begin, dia.@10, d@20, d30, d40, d50
4j13, 50.2mm, 24mm, 2.513, 2.513, 2.230, 1.800, 1.400
5J22, 51.32, unk, 2.53mm
5dl31 58.18mm , 24.85mm, 2.45, 2.42, 2.33, 1.82, 1.28
5J11, 53.98mm, 27.75mm, 2.47, 2.42, 2.32, 1.85, 1.44
5L1, 58.11mm, 26.7mm, 2.42, 2.42, 2.27, 1.68, 1.20

I have one or two of these needles, and more on the way I will add pics that match the specs, and for the following eventually add specs that match.

Thanks to Jus_ME for the pics, and possibly some measurements at a later time.

 

[deeeebeeeeee]

50.2mm, 24mm, 2.513, 2.513, 2.230, 1.800, 1.400
5J22, 51.32, unk, 2.53mm
5J11, 53.98mm, 27.75mm, 2.47, 2.42, 2.32, 1.85, 1.44

 

[deeeebeeeeee]

I just realized when looking at the needles I just got that i might have to go to a #4 series to get one that is thin enough early enough in the throttle range for the O-0 Needle Jet (that is the largest available for 249 / 332 series NJ)

I tried looking at a needles specs and using that to choose a needle. The longest needle in the picture would probably work well if I could move the clip cutouts down to where it was only a couple mm longer then the 5j22 (stock).

I just realized that at my local yamaha dealer, when I ask for jets he brings out three medium sized boxes, filled with all sorts of jets and needles, might be a good idea to drop in and pick out a couple needles visually, using the measured sizes as a guide since I am really looking for a needle 8 to 10 hundredths of a mm thinner overall. To deal with the thinner NJ.

I am begging to think that one with a little less taper (g,h,i) might be the ticket, so that I can set it a little richer at 1/4 to half without getting too rich from half to MJ). I say this because it seems like alot of blasters tend to get lean just under half throttle, or get too rich just before getting up in the M. Jet. So maybe a shorter needle like the 5j22 isn't the answer as much as a little less taper or a little longer tip. Although it seems that Most of the needles that are longer have more on top not the bottom. Which is a consideration for the engine characteristics in general.

Then I have to consider the effect, raising the exhaust 1.3mm and widening by 2.5mm, opening up the intake slightly, cleaning up the transfers, and raising the main transfers .3 mm, will have on jetting.
Hence the visual search for needles with various amounts of difference, in length, average size and taper, hopefully when I start tuning I will the perfect needle in my kit.

Although there are those who are willing to help, I am kinda on my own on this because there is no guide or clear cut way to get it right whether you can feel it or not. With the pilot jet, if you need to go too far on the air screw then you change up/down in size.
When it comes to setting a needle that is already matched to the motor and Needle Jet, you can plug chop half throttle.
Main jet chop @ WOT.

I guess you could chop at half throttle to verify the proper height for each needle, then run around just under 3/8 throttle and around just over 5/8 throttle and see how it feels, it would take a case of plugs and hacksaw blades.

If anyone has any hints, guidelines or corrections when it comes to tuning or needle selection please let me know.