Jet Needle Overview - Polaris 2003 Pro X Service Manual

CARBURETION
Mikuni TM 38 / TM 40 Jet Needle Overview
Leaner
1
2
3
4
5
Richer
O.D.
Straight Portion
E -- Taper
J -- Taper
3.4
This needle (example) is a 9DH01--57. The first number is
the approximate overall length in 10mm increments of the jet
needle. The 9 indicated the needle is approximately 90mm
but less that 100mm in length.
The letters on the jet needle indicate the angle of both ta-
pers. The first letter designates the taper angle of the top
section (closest to the grooves) and the second letter desig-
nates the angle of the bottom taper. The taper angles are
graduated in 15' (15 minute) increments. The jet needle
marked 9DH01--57 would have a top taper of 1_0' and a bot-
tom taper of 2_0'.
The number following the letters on the jet needle is the seri-
al number and it varies with individual jet needles.
The last number, 57, indicates that the outside diameter is
2.57mm. The smaller the O.D., the richer the mixture.
9
Overall Length in 10mm Increments
D
Taper of top section of needle
H
Taper of bottom section of needle
01 Serial Number
- - 57
Outside Diameter