Checking and readjusting idle, emission value

AP07.20-P-0750A

Checking and readjusting idle, emission value

20.11.2019

Engine

115 in model 460

Connection scheme for measuring equipment:

1

Diagnostic socket

3

Adapter

4

Trigger clamp

5

Digital tester

1

Stop screw

6

Vacuum hose

7

Jam nut

8

Diaphragm rod

9

Adjustment screw

10

Throttle valve lever

11

Adjusting nut

3

Idle speed setting screw

4

Retaining cap

5

CO value setting screw



Check

 Warning

Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.

Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.

AS00.00-Z-0005-01A

 Danger

Risk of death when working on component parts and systems with U >= 30 V alternating voltage (AC) or U >= 60 V direct voltage (DC)

Do not touch damaged or defective live component parts and lines or non-insulated electrical connections and lines.

AS00.00-Z-0035-01A

1

Check damper oil level in carburetor and correct if necessary.

AP07.20-P-0711A

2

Connect test equipment.


Ignition:OFF
- Oil remote thermometer
- Rpm tester or digital test equipment
(see connection scheme for measuring equipment)
- CO tester

 Commercially available devices/tools
Digital test equipment (with adapter)

3

Check intake system for leaktightness.

 Engine: idle

Spray all sealing points with iso-octane DIN 51756 or pure benzine. If the engine speed changes, there is a leak.

4

Unhook throttle control linkage from carburetor.

5

Check throttle valve shaft for ease of movement.

6

Check whether stop screw (1) is touching closed throttle stop.

 If necessary, release the compression spring with the adjusting nut (11) until the stop screw (1) touches the closed throttle stop.

7

Hook throttle control linkage onto carburetor.

 Manual transmission: Unstressed

Automatic transmission: Unstressed in extended state

8

Check firing point.

AP15.10-P-1561G

9

Check idle speed and adjust with setting screw (3) if necessary.

 Engine: idle
Selector lever position: P
Refrigerant compressor: OFF
Engine oil temperature: approx. 80 °C

Engine 115.973 in model 460Idle speed (oil temperature 75...85 °C)

*BE07.20-P-1001-01A

Basic setting of throttle valve, see:



Repair instructions for off-road vehicles 07.2-323.

10

Check idle speed exhaust value

 Engine: idle
Selector lever position: P
Refrigerant compressor: OFF
Engine oil temperature: approx. 80 °C

Detach crankcase bleed line from air filter.

Engine 115.973 in model 460Idle speed exhaust value (oil temperature 75...85 °C)

*BE07.20-P-1002-01A

11

Adjust idle speed exhaust value

 Detach locking plug (4).
Adjust CO value using adjustment screw (5)
Unscrew = richer
Screw in = leaner
Briefly increase engine speed using throttle control linkage, check CO value again, readjust it.
Press locking plug (4) onto adjustment screw (5).
Plug crankcase bleed line into air filter.

12

Check/correct setting of throttle vacuum control.

AP07.20-P-0750-01A

Engine 115.973 in model 460Distance between throttle lever and adjustment screw for throttle vacuum control

*BE07.20-P-1003-01A

13

Check engine running

 Parking brake: apply
Engine: idle
Selector lever position: D
All consumers: ON
The engine must run smoothly though all speeds.
If necessary, readjust rpm with setting screw (3).

Stromberg carburetor system check values

Number

Designation

ENGINE 115.973

BE07.20-P-1001-01A

Idle speed (oil temperature 75...85 °C)

Vacuum hose plugged on

1/min

800...900

Vacuum hose detached

1/min

1200...1400

Stromberg carburetor system check values

Number

Designation

ENGINE 115.973

BE07.20-P-1002-01A

Idle speed exhaust value (oil temperature 75...85 °C)

% CO

1,0...2,0

Stromberg carburetor system check values

Number

Designation

ENGINE 115.973

BE07.20-P-1003-01A

Distance between throttle lever and adjustment screw for throttle vacuum control

mm

0,1