The Husqvarna 550XPG and 550XPG TrioBrake chainsaws come equipped with handles and carburetor heaters to ensure proper functioning. If you experience any issues with the heaters, the following guide will be helpful in troubleshooting and resolving them.
Additionally, a comprehensive Workshop Service Manual with detailed instructions, diagrams, and further repair information, including dismantling and refitting procedures, is available for download. A brief summary of the guide is provided below.
Table of Contents
Husqvarna 550XPG, 550XPG TrioBrake Parts List, Operator Manual, and carburetor manual are also available to view or download as a PDF which can be read on any device or easily printed.
- Handle heater and carburetor heater for Husqvarna 550XPG, and 550XPG TrioBrake chainsaw
Certain chainsaw models can be fitted with a handle heater and a carburetor heater and comprise the following:
- Generator
- Power switch
- The heating element in the rear handle
- Handlebar with the heating element
- Carburetor heating element
- Thermostat
Troubleshooting
It is possible to troubleshoot with most parts fitted to the chain saw. Troubleshooting requires:
- Ammeter
- Ohmmeter
- Coolant spray
Oxidation of the connectors in the heating elements in the rear handle and the power switch’s contact plate is the most common fault.
Troubleshoot as follows:
1. Loosen the screw holding the earth cable
See Figure 1.
2. Measure the resistance
Measure the resistance in the whole circuit by connecting the multimeter to the earth cable and a properly cleaned cylinder. See Figure 2.
A correct reading with the power switch set to “OFF” = oo Ohm. A correct reading with the power switch set to “ON” = 4 to 5 Ohms
3. Unscrew the two screws on the front handle and remove the cover
See Figure 3.
4. Carefully remove the power switch using a flat screwdriver or similar tool
See Figure 4
5. Check that the contact plate in the power switch is intact and free of dirt and oxidation
See Figure 5. Clean and assemble the power switch. Carry out a resistance test according to step 2.
6. Loosen the cables and remove the cable bracket
See Figure 6.
Troubleshooting the heating element, rear handle
7. Connect the multimeter
As outlined in Figure 7 and measure the resistance in the rear handle’s heating element. The multimeter reading should indicate between 0.5 and 1.2 Ohm. Replace the heating element if you get another reading.
Troubleshooting the heating element, front handle
8. Connect the multimeter
As outlined in Figure 8 and measure the resistance in the front handle’s heating element. The multimeter reading should indicate between 3 and 5 Ohm. Replace the front handle if you get another reading.
Troubleshooting the generator
Connect the multimeter to the generator cable and a properly cleaned cylinder as outlined in Figure 9. The multimeter reading should indicate between
0.4 and 1.1 Ohm. Replace the generator if you get another reading.
Troubleshooting the carburetor’s heating element and thermostat
10. Connect the multimeter
as outlined in Figure 10. The measurement should be carried out at normal room temperature (20°C/68°F) and should indicate in that case 0 A.
Cool the thermostat for instance with a coolant spray or a similar agent. The ammeter should then have a reading of 0.5 A.
Replace the heating element and the thermostat if you get another reading.
Replacing the heating element in the rear handle
1. Remove the cylinder cover
Loosen the screw on the left-hand side of the rear handle and dismantle the handle insert with the attached cables. See Figure 11.
2. Fit the new handle insert with the heating element
Run the cabling through the handle out through the openings in the front handle. Connect the cable and fit the:
- Cable bracket with cabling
- Power switch
- Cover
- Cylinder cover
- Tighten the screw for the earth cable.
Replacing the front handle
1. Dismantle the following parts
- Clutch cover
- Bar and chain
- Cylinder cover
2. Loosen the screws
Screw F undo and remove the front handle.
3. Fit the new handle
Run the cabling through the openings and tighten the screws F. Tightening torque 3-4 Nm. Connect the cabling and fit the following parts:
- Cable bracket with cabling
- Power switch
- Cover
- Cylinder cover
- Tighten the screw for the earth cable.
- Bar and chain
- Clutch cover
Husqvarna 550XPG and 550XPG TrioBrake Handle heater and carburetor heater Repair