Toro ProLine 20 HP, Operator'S Manual

Page: 36 / 48

Maintenance
34
Adjustment Procedure
The by–pass valve should be adjusted to deliver best
performance for the size (weight) mower you have.
The by–pass valve factory setting is 1/2 turn out.
The following values can be used as initial settings
for different size mowers:
62” 1/6 turn out
52” 1/2 turn out
44” 1 turn out
36” 1 turn out
9. Loosen large jam nut several turns (Fig. 30).
10. Gently close by–pass valve (Fig. 30).
IMPORTANT: Do not over–tighten valve or
needle and seat may be damaged. Do not
exceed 50 inch pounds to close valve.
11. Open by–pass valve 1/2 turn (Fig. 30).
12. Tighten jam nut to lock the adjustment (Fig. 30).
13. Repeat “Test Procedure” to check for proper
operation.
IMPORTANT: By–pass valve adjustment is
very sensitive, do not adjust more than 1/6
turn (one flat) at a time.
14. If the machine is too aggressive, the valve needs
to be open further.
15. If the machine is un–responsive, the valve needs
to be closed further.
16. Repeat “Test Procedure” to check for proper
operation. Re-adjust the by–pass valves until
proper performance is achieved.
1
m–3098
1
2
Figure 30
1. By-pass valve 2. Jam nut