Vacuum Timing Control Device - Toro Workman 3000 Series Service Manual

Vacuum Timing Control Device

1. Start engine and run at idle.
2. Remove vacuum hose from vacuum controller. Plug
disconnected vacuum hose. Connect vacuum pump to
nipple.
3. Add vacuum on vacuum pump gradually and check
advance. Timing should advance smoothly with in­
creased vacuum.
Symptom
Excessive advance
Start–up advance too sudden
Inadequate advance or slow
change in advance
No advance
Workman 3000/4000 Series
Possible Cause
Worn or damaged vacuum
controller spring
Damaged spring
Breaker base malfunction
Damaged diaphragm
Page 3 – 35
Figure 50
<Reference> Centrifugal characteristics
15
10
5
0
–200 –300 –400
–100
0
(–7.9) (–11.8) (–15.7) (–19.7)
(–3.9)
Pressure [mm Hg (in. Hg)]
Figure 51
Liquid Cooled Gas Engine
U8EL023
–500