Wacker Neuson WM 80 User Manual

Carburetor Basics WM 80 Repair
54 wc_tx000522gb.fm
5.3 Versions of Tillotson Carburetor
See Graphic: wc_gr002889
1) Dual Needle
Dual needle carburetors have mixture needle valves that are
adjustable. One of the valves (a) adjusts the high-speed jet (H) and the
other valve (b) adjusts the low-speed jet (L). The needle valves operate
by increasing or decreasing the size of the fuel passage to the
discharge ports.
2) Single Needle
Single needle carburetors use a fixed, high-speed fuel jet. No
adjustment of this jet can be made. A low-speed-mixture needle valve
(c) is used to adjust the low-speed jet (L) which controls the idle mixture
and the idle speed. The needle valve operates by increasing or
decreasing the size of the fuel passage to the discharge ports.
3) Fixed-jet, Primary-idle-bypass
Fixed-jet, primary-idle-bypass versions use fixed high-speed and fixed
low-speed jets. No adjustment of either jet can be made. A separate
bypass circuit provides the air/fuel mix to run the engine at idle.
wc_gr002889
1
2
3
a
b
c
H
L

Wacker Neuson WM 80 Specifications

General

Brand	Wacker Neuson
Model	WM 80
Category	Engine
Language	English