duneracerweston
Well-Known Member
Jet Needles: Series: 4 | 5 | 6 | 7
(a)=Needle Length (mm)
(b)=Length between point (x) and the beginning of taper point (y)
Variables in needles:
Overall length
Taper
Distance from clip position to taper begining.
Major diameter where it interferes with the needle jet at idle.
Selection Guide:
Often we are asked what needle to use when an OEM needle is no longer available. The way Mikuni Needle numberings work is:
The first number is the length series. Lets take the series 4 needle. It could be 40.00-49.99mm in length. In turn a 5 could be 50.00-59.99mm in length.
The second and sometimes third characters being letters describe the taper from the clip end to the tip in 15minute (1/4th of a degree) increments. For example "B" is 30 seconds, and "E" is 1 degree, 15 seconds. Therefore a "BE" would be a taper starting out at 30 seconds (1/2 degree), followed by a second taper of 1min 15sec.
The last digit be it one or two characters is the suffix or revision number. Example. 4D3, and 4D8 are the same style needle, similar in length and taper. However the taper may begin higher up on the needle than the other. This would make a smaller tip diameter, or a shorter needle. If shims, or clip positions were incorporated on one needle it is possible that it may effectively perform like the other. For this reason we sometimes suggest ordering a 4D3, or 4D8 for example if an OEM application calls for a 4D5 which is not available, instead of a 4E?
Lastly there is sometimes a number designated by OEM's and this designates the clip position. Example: 5DP3-4. However this "-#" designation is not part of the needed part number.
One last note: A suffix number has the following unknown variables between one needle and another. Exact length, Major OD, Point of begining of taper in reference to clip position. Without physically measuring them there is no way to determine these characteristics just by looking at the part number.
a b D-1 D-2 D-3 D-4 D-5
4D3 50.3 25.3 2.511 2.511 2.421 2.253 2.100
4D8 50.3 22.0 2.519 2.519 2.381 2.211 2.000
4D10
Not available
4D20
Not available
4DG6 50.3 24.0 2.518 2.518 2.405 2.118 1.850
4DG8 50.3 24.0 2.518 2.518 2.405 2.118 1.850
4DH7 50.3 23.0 2.518 2.518 2.386 2.090 1.790
4DH11
Not available
4DH22
Not available
4E1 50.3 28.0 2.515 2.515 2.345 2.127 1.924
4EJ4
Not available
4F6 50.5 25.3 2.514 2.514 2.400 2.145 1.876
4F10 50.2 24.5 2.513 2.513 2.385 2.1?5 1.?7?
4F15 50.3 26.5 2.512 2.512 2.400 2.120 1.881
4J6 50.3 24.2 2.513 2.513 2.233 1.827 1.472
4J11 41.5 21.3 2.512 2.506 2.188 1.776
4J13 50.2 24.0 2.513 2.513 2.230 1.800 1.400
4L6 50.3 24.5 2.515 2.515 2.178 1.660 1.190
4L13 45.1 25.0 2.51? 2.51? 2.339 1.842
4P3 50.5 25.0 2.510 2.506 2.436 2.284 2.122
Series 5
a b D-1 D-2 D-3 D-4 D-5 D-6
5C4
5D1
5D5
5D6 59.3 27.5 2.515 2.515 2.460 ? 2.290 2.120
5D120 59.1 ? 28.2 2.520 2.520 2.429 ? 2.311 1.???
5DL13
5DP2
5DP7
5DP22
5E3 58.0 27.4 2.518 2.518 2.419 2.??? 1.???
5E13
5EH7
5EJ8
5EJ11
5EJ13
5EL8
5F12
5F15
5F18
5F21
5FJ9 59.2 35.0 2.517 2.517 2.517 2.364 2.021
5FJ10
5FL7
5FL11
5FL14
5FP8
5FP17
5J6
5J9 N/A
5L1
5I4
Series 6
a b c D-1 D-2 D-3 D-4 D-5 D-6
5DH21 N/A
6CF1 N/A
6D16
6DH2
6DH3
6DH4 62.3 25.5 2.520 2.520 2.440 2.258 1.915 1.575
6DH7
6DH8
6DJ30
6DP1
6DP4
6DP5
6DP10
6F3
6F4
6F5
6F8
6F9
6F13
6F15
6F22
6F16 69.1 30.0 18.7 2.518 2.485 2.485 2.372 2.104 N/A
6FJ6
6FJ11 N/A
6FJ40
6FJ41
6FL14
6FM46
6H1
6J1
6J3
6L1
6N1
Series 7
a b D-1 D-2 D-3 D-4 D-5 D-6 D-7
7DH2
7DH3
7DH4
7DH5
7F6
7F7
found this on a different site may help others if they are trying to figure out what they mean
(a)=Needle Length (mm)
(b)=Length between point (x) and the beginning of taper point (y)
Variables in needles:
Overall length
Taper
Distance from clip position to taper begining.
Major diameter where it interferes with the needle jet at idle.
Selection Guide:
Often we are asked what needle to use when an OEM needle is no longer available. The way Mikuni Needle numberings work is:
The first number is the length series. Lets take the series 4 needle. It could be 40.00-49.99mm in length. In turn a 5 could be 50.00-59.99mm in length.
The second and sometimes third characters being letters describe the taper from the clip end to the tip in 15minute (1/4th of a degree) increments. For example "B" is 30 seconds, and "E" is 1 degree, 15 seconds. Therefore a "BE" would be a taper starting out at 30 seconds (1/2 degree), followed by a second taper of 1min 15sec.
The last digit be it one or two characters is the suffix or revision number. Example. 4D3, and 4D8 are the same style needle, similar in length and taper. However the taper may begin higher up on the needle than the other. This would make a smaller tip diameter, or a shorter needle. If shims, or clip positions were incorporated on one needle it is possible that it may effectively perform like the other. For this reason we sometimes suggest ordering a 4D3, or 4D8 for example if an OEM application calls for a 4D5 which is not available, instead of a 4E?
Lastly there is sometimes a number designated by OEM's and this designates the clip position. Example: 5DP3-4. However this "-#" designation is not part of the needed part number.
One last note: A suffix number has the following unknown variables between one needle and another. Exact length, Major OD, Point of begining of taper in reference to clip position. Without physically measuring them there is no way to determine these characteristics just by looking at the part number.
a b D-1 D-2 D-3 D-4 D-5
4D3 50.3 25.3 2.511 2.511 2.421 2.253 2.100
4D8 50.3 22.0 2.519 2.519 2.381 2.211 2.000
4D10
Not available
4D20
Not available
4DG6 50.3 24.0 2.518 2.518 2.405 2.118 1.850
4DG8 50.3 24.0 2.518 2.518 2.405 2.118 1.850
4DH7 50.3 23.0 2.518 2.518 2.386 2.090 1.790
4DH11
Not available
4DH22
Not available
4E1 50.3 28.0 2.515 2.515 2.345 2.127 1.924
4EJ4
Not available
4F6 50.5 25.3 2.514 2.514 2.400 2.145 1.876
4F10 50.2 24.5 2.513 2.513 2.385 2.1?5 1.?7?
4F15 50.3 26.5 2.512 2.512 2.400 2.120 1.881
4J6 50.3 24.2 2.513 2.513 2.233 1.827 1.472
4J11 41.5 21.3 2.512 2.506 2.188 1.776
4J13 50.2 24.0 2.513 2.513 2.230 1.800 1.400
4L6 50.3 24.5 2.515 2.515 2.178 1.660 1.190
4L13 45.1 25.0 2.51? 2.51? 2.339 1.842
4P3 50.5 25.0 2.510 2.506 2.436 2.284 2.122
Series 5
a b D-1 D-2 D-3 D-4 D-5 D-6
5C4
5D1
5D5
5D6 59.3 27.5 2.515 2.515 2.460 ? 2.290 2.120
5D120 59.1 ? 28.2 2.520 2.520 2.429 ? 2.311 1.???
5DL13
5DP2
5DP7
5DP22
5E3 58.0 27.4 2.518 2.518 2.419 2.??? 1.???
5E13
5EH7
5EJ8
5EJ11
5EJ13
5EL8
5F12
5F15
5F18
5F21
5FJ9 59.2 35.0 2.517 2.517 2.517 2.364 2.021
5FJ10
5FL7
5FL11
5FL14
5FP8
5FP17
5J6
5J9 N/A
5L1
5I4
Series 6
a b c D-1 D-2 D-3 D-4 D-5 D-6
5DH21 N/A
6CF1 N/A
6D16
6DH2
6DH3
6DH4 62.3 25.5 2.520 2.520 2.440 2.258 1.915 1.575
6DH7
6DH8
6DJ30
6DP1
6DP4
6DP5
6DP10
6F3
6F4
6F5
6F8
6F9
6F13
6F15
6F22
6F16 69.1 30.0 18.7 2.518 2.485 2.485 2.372 2.104 N/A
6FJ6
6FJ11 N/A
6FJ40
6FJ41
6FL14
6FM46
6H1
6J1
6J3
6L1
6N1
Series 7
a b D-1 D-2 D-3 D-4 D-5 D-6 D-7
7DH2
7DH3
7DH4
7DH5
7F6
7F7
found this on a different site may help others if they are trying to figure out what they mean
