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
Summary of Contents for WM 80
Page 1: ...0162695en 003 0610 0 1 6 2 6 9 5 E N Repair Manual Engine WM 80...
Page 4: ...Foreword 4 wc_tx001528gb fm...
Page 27: ...WM 80 Maintenance wc_tx000520gb fm 27 wc_gr001168 a b c d k i h...
Page 35: ...WM 80 repair Starting and Ignition wc_tx000521gb fm 35 wc_gr002882 a d e b c...
Page 41: ...WM 80 repair Starting and Ignition wc_tx000521gb fm 41 wc_gr002885 S N d a c b...
Page 43: ...WM 80 repair Starting and Ignition wc_tx000521gb fm 43 wc_gr002886 a d f f e k c g i h j b...
Page 63: ...WM 80 Repair Carburetor Basics wc_tx000522gb fm 63 Notes...
Page 65: ...WM 80 Repair Carburetor Basics wc_tx000522gb fm 65 d d d d d 1 2 3 e 4 f g 5 6 h wc_gr007414...
Page 71: ...WM 80 Repair Carburetor Replacement wc_tx000522gb fm 71 Notes...
Page 109: ...WM 80 Repair Disassembly and Assembly wc_tx000523gb fm 109 wc_gr002935 d a b e c d...
Page 111: ...WM 80 Repair Disassembly and Assembly wc_tx000523gb fm 111 wc_gr002937 a b d e c f...
Page 113: ...WM 80 Repair Disassembly and Assembly wc_tx000523gb fm 113 wc_gr002941 a b c...
Page 119: ...WM 80 Repair Disassembly and Assembly wc_tx000523gb fm 119 wc_gr002940 a c d e f b...
Page 121: ...WM 80 Repair Disassembly and Assembly wc_tx000523gb fm 121 b c f e g d c wc_gr002907...
Page 123: ...WM 80 Repair Disassembly and Assembly wc_tx000523gb fm 123 h wc_gr002908...
Page 127: ...WM 80 Repair Disassembly and Assembly wc_tx000523gb fm 127 a wc_gr002910 b OK OK...
Page 129: ...WM 80 Repair Disassembly and Assembly wc_tx000523gb fm 129 wc_gr002911 a b c e f d g h...
Page 131: ...WM 80 Repair Disassembly and Assembly wc_tx000523gb fm 131 wc_gr002912 f e a h g d a b c a f e...
Page 133: ...WM 80 Repair Disassembly and Assembly wc_tx000523gb fm 133 a c d wc_gr002913 e b...
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