KR-1S.co.uk Forum

The KR bikes had a few different needles over the models like 99E and N68 etc but what are the different dimensions

Taper
length
Diameter

the overall needle Length = 57mm

used dial vernier (so rough and no 99's handy to measure)... by looks...
N68A = 2.435 mm dia but is 'Twin Taper' - see Sudco specs ~= JJH or maybe JLH (they are NOT 2.75 dia 'HarleyD' needles as quoted elsewhere)
N68X = 2.395 dia ~= JJD
... so needle N68A is slightly leaner than N68X all the way along its length (at corresponding points N68A being around +0.05mm more diameter against N68X)

JJH (Taper, L1, Diameter)
length (overall) = 57mm needle
Taper = 3°
L1 = 25.4 mm
Diameter = 2.435 mm

people with Banshees/blasters etc seems to like the N68A (twin tapered) more the JJH

have you tried somebody elses 28 carbs? compared with yours
youve gone 2 screws out on 45 pilots so why havent you gone bigger pilots still?

headcoats wrote:I went to #160 mains in the summer and lost 4.5 BHP and it wouldn't rev over 9 grand,so went back to 152's

Anything less than #45 pilots i get a horrible jerking on light throttle and only going up on the pilots seemed to cure it

But i guess the thing i need to know is about these fabled JJH needles

if youre running problem is less than half throttle it wont be mainjet related >>> Pilot >>> Needle (dia...clip...taper) >>> Mainjet



...visually - difficult to tell these two apart



there is a typo error in diagram below
if the needle is 2.435 dia if cant be 2.515mm further along the taper...

headcoats wrote:I have bought some needle shims for my PWK carbs and when they arrived they just look like normal washers

One measures 0.71mm and the other 0.59mm

For these clips to lift just half a clip position what thickness should they be

...pretty much half of 0.9mm for half a clip
= 0.45mm