After Replacing The Carburettor Autotune; Engine Adjustment - Husqvarna 545RXT AT Workshop Manual

Carburettor

WARNING! When the engine is tested in connection with carburettor adjustment, the clutch and

clutch cover must be mounted together with the shaft and gear head. A loose clutch can result in

serious personal injury.

NOTE! Do not remove the AutoTune unit from the carburettor.

NOTE! When replacing the carburettor, a firmware download is required on the new unit and it has to pass

the test "autotest" in Common service tool (CST) before use. See instruction in CST (documents->Handheld-

>AutoTune).

The AutoTune unit adjusts the fuel mixture continuously during operation. Manual adjustment of the carburettor by H

and L needles and the T-screw no longer applies.

Always do engine adjustment on a warm engine.

•

Autotune will adjust the L value when the product operates at idle speed.

•

Autotune will adjust the H value when the product operates unloaded with Wide Open Throttle (WOT). Cutting

equipment must run freely in the air.

When the sequence below is started, do not shut the engine off until all steps are finished.

1. Attach a cutting equipment that is specified as an approved accessory

2. If a trimmer head is mounted, make sure that the line is cut by the guard knife

3. Run the engine warm. It takes approximately 3 min.

4. Run the product for 30 seconds with WOT, then release throttle. Repeat this three times.

5. Let the product run on idle for 5 min.

To measure the idle speed, hold the tachometer (See

Service tools) as shown in figure 43.

Make sure that the idle speed is according to the

technical data, see "17 Technical data" on page 7. If the

idle speed is not according to the technical data, follow

the steps in 9.9.

44 – English

Fig. 43