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
Needles !!!
-
- Avgas Sniffer
- Posts: 2120
- Joined: Sat Jun 09, 2007 10:10 am
- Location: Pig on the wall country
Needles !!!
Can it yer old boiler
-
- Premix Junkie
- Posts: 1588
- Joined: Wed May 16, 2007 2:24 am
N68A vs N68X PWK28 needles for KR-1
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?

...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...

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

...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...

Last edited by KR-1R on Mon Feb 28, 2011 11:56 pm, edited 1 time in total.
-
- Premix Junkie
- Posts: 1588
- Joined: Wed May 16, 2007 2:24 am

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
Last edited by KR-1R on Mon Feb 21, 2011 11:24 pm, edited 1 time in total.