Husqvarna 128CD/128LD service: manual and head identity
Identify the 128CD or 128LD type before ordering a plug or cutting head. Husqvarna’s September 2023 manual for LT28CCHV and LT28CSHV specifies Champion QCJ-8Y at 0.6 mm.
Those models use different head threads; a family-wide “128” kit does not establish compatibility. Match the complete product identity and manual revision.
The current support manual identifies a later configuration
Husqvarna’s 128CD support page links the September 4, 2023 operator’s manual (215-005). Its technical table gives 28 cc displacement and a 400 ml fuel tank for both listed types. Record the type code and document revision with the parts order.
| Model | Thread | Listed cutting-attachment guard |
|---|---|---|
| 128CD | 3/8RH | 5450311-01 |
| 128LD | M10 L | 5450309-01 |
A head offered for one of those threads is not identified for the other just because both are called T25. Thread direction and size are part of the fit, along with the guard and approved attachment. Ask for the full part identity before installing a replacement head.
The shaft has an explicit 30-hour instruction
The dedicated procedure says to grease the end of a two-piece drive shaft after each 30 hours. Its schedule also lists periodic shaft and bevel-gear checks. Retain the specific procedure alongside the calendar list rather than assuming a once-a-year service covers every usage pattern.
For an example two operating hours each week, 30 hours arrives after 15 weeks. The manual says its schedule is calculated from daily use and intervals differ with other usage. Keep actual hours and inspection findings so a low-use calendar reminder does not stand in for the 30-hour procedure.
Clean the element by its actual instructions
The 2023 manual specifies warm soapy water for its air filter, drying before refitting and replacement if damaged or too dirty to clean. That differs from the non-washable felt filter on some other trimmers. Do not transfer cleaning advice between different elements.
Stop for an attachment moving at idle, a fuel leak or damaged safety parts. Repairs outside the owner-manual tasks belong with an approved service center. The fuel mixture, throttle controls, guard and fitted attachment all need the instructions for the actual machine.
Prepare the coupling, fuel and storage together
After shaft service, the locking button must pass through the coupling hole and the knob must be fully tightened before operation. A joint that merely slides together is not the completed assembly. The matching manual, pages 10–13, covers assembly, fuel preparation and storage.
Its fuel ratio is 50:1 with suitable air-cooled two-stroke oil. Mix in a clean container: half the gasoline, all the measured oil, shake, then add the remaining gasoline and shake again. Prepare no more than 30 days of mixture.
Stop the engine and let it cool before refueling; move at least 3 m (10 ft) from that location before starting.
Before long storage, empty the tank and operate the purge bulb to clear fuel, disposing of it appropriately. Keep the machine dry and ventilated, away from ignition sources and children. A fresh fuel mix does not repair a leaking hose or an insecure attachment.
Husqvarna 128CD and 128LD string trimmers: fuel mix, spark plug and maintenance
The Husqvarna 128CD and 128LD run on a 1:50 (2%) mix, which is the manual’s approximate ounce example of 2½ US fluid ounces of two-stroke oil per gallon of unleaded gasoline, and use a Champion QCJ-8Y spark plug for the September 2023 LT28CCHV/LT28CSHV manual gapped 0.6 mm (0.024 inch). The tank holds 0.4 liter. Husqvarna schedules the spark plug and air filter for replacement monthly and the air filter for cleaning every 25 hours.
Stop the engine and disconnect the spark plug before servicing, and let the muffler cool; the catalytic converter muffler stays hot during and after use.
A 28 cc two-stroke trimmer that runs on a 50:1 mix
The Husqvarna 128CD and 128LD are 28 cubic centimeter two-stroke string trimmers rated at 1.1 horsepower (0.8 kW), weighing about 10 and 11 pounds without fuel and attachment. The engine must always run on a mix of unleaded gasoline and two-stroke oil, and Husqvarna specifies 1:50 (2%).
| Item | Specification |
|---|---|
| Engine | 28 cc (1.7 cu in) two-stroke; bore 35 mm, stroke 28.7 mm |
| Fuel mix | 1:50 (2%) two-stroke oil to unleaded gasoline, octane 87 or higher |
| Spark plug | Champion QCJ-8Y (September 2023 manual) resistor plug or equivalent |
| Spark plug gap | 0.024 in (0.6 mm) |
| Fuel tank | 0.4 L (0.85 US pint) |
| Idle speed | 2,800 to 3,200 RPM |
| Recommended maximum speed | 10,000 RPM (128CD); 11,000 RPM (128LD) |
| Output shaft speed | 8,000 RPM |
| Carburetor and ignition | Zama carburetor; Walbro CD ignition |
Mix table at 1:50
| Gasoline | Two-stroke oil |
|---|---|
| 1 US gallon | 2½ US fl oz |
| 2½ US gallons | 6½ US fl oz |
| 5 US gallons | 12⅞ US fl oz |
Fill half the gasoline first, add all the oil, shake, then add the rest and shake again. Do not mix more than a month’s supply. Never use oil made for water-cooled outboard engines or for four-stroke engines; the manual allows Husqvarna oil or another high-quality two-stroke oil, including a synthetic.
After the engine has used 8 to 10 tanks of fuel it is run in.
The Husqvarna 128CD and 128LD string trimmers schedule
| When | What |
|---|---|
| Daily | Check the throttle trigger and lockout, the stop switch, fuel leaks, that the cutter stops turning at idle, and the guard and harness. |
| Every 25 hours | Clean the air filter, sooner in dust: wash it in warm soapy water, rinse, and let it dry fully. |
| Weekly | Clean the outside of the spark plug and check the gap; clean the cooling fins and air intake; check the starter cord; clean the air filter. |
| Monthly | Clean the fuel tank and change the fuel filter in the tank; check fuel lines and the clutch; replace the spark plug; change the air filter. |
| Bevel gear (128LD) | Keep it three-quarters full of Husqvarna special grease; it does not normally need changing except after repairs. |
Husqvarna says the air filter cannot be cleaned completely after long use and must be replaced at regular intervals, and that a damaged filter must always be replaced.
Parts to buy for the Husqvarna 128CD and 128LD string trimmers
| Part | Part number | Notes |
|---|---|---|
| Air filter | 530150253 | Fits the 128 LD, 128 CD, 128 L, 128 R, 125 L, 125 R and related trimmers. |
| Spark plug | Champion QCJ-8Y (September 2023 manual) | Gap 0.6 mm (0.024 in). |
Husqvarna also sells a 128 series trimmer tune-up kit with a fuel filter, air filter and spark plug.
1:50
Fuel mix
2½ oz of oil per US gallon.
QCJ-8Y (September 2023 manual)
Champion spark plug
Gap 0.6 mm (0.024 in).
0.4 L
Fuel tank
0.85 US pint.
Husqvarna 128CD and 128LD string trimmers: questions
What is the fuel mix for a Husqvarna 128LD?
1:50 (2%), which is the manual’s approximate ounce example of 2½ US fluid ounces of two-stroke oil per US gallon of unleaded gasoline. For 2½ gallons use 6½ ounces, and for 5 gallons use 12⅞ ounces.
What spark plug does a Husqvarna 128LD use?
A Champion QCJ-8Y (September 2023 manual) resistor plug or equivalent, with the electrode gap set to 0.024 inch (0.6 mm). Husqvarna warns that the wrong plug type can damage the engine.
How much fuel does the Husqvarna 128LD tank hold?
0.4 liter (0.85 US pint). Mix only what you will use within a month, and empty and clean the tank if the trimmer will sit unused.
What gasoline should I use in a Husqvarna 128CD?
Unleaded gasoline with an octane rating of at least 87. Below that, knocking can occur and raise engine temperature. Use a higher octane for continuous high-speed work.
What oil do I mix in a Husqvarna 128LD?
Husqvarna two-stroke oil, or another high-quality two-stroke oil including synthetic, at 1:50. Never use oil for water-cooled outboard engines or four-stroke engine oil.
How often do I clean the 128LD air filter?
Every 25 hours, or more often in dust, and weekly per the schedule. Wash it in warm soapy water, rinse out the soap and let it dry before refitting. Replace it monthly per the maintenance list.
How often do I replace the 128LD spark plug?
The manual’s monthly list says to replace it, and the weekly list says to clean the outside and check the gap. Use the Champion QCJ-8Y (September 2023 manual) or equivalent.
What is the idle speed on the Husqvarna 128LD?
2,800 to 3,200 RPM. The recommended maximum speed is 10,000 RPM for the 128CD and 11,000 RPM for the 128LD.
How big is the Husqvarna 128LD engine?
28 cubic centimeters (1.7 cu in), a two-stroke rated 1.1 horsepower (0.8 kW). It has a Zama carburetor and a Walbro CD ignition.
How much grease does the 128LD bevel gear need?
Keep it three-quarters full of Husqvarna special grease. It is filled at the factory and does not normally need changing except when repairs are carried out.
What is the break-in on the Husqvarna 128LD?
The engine is run in after 8 to 10 tanks of fuel. Husqvarna designed it to reduce harmful emissions and says to keep up all required maintenance.
What is the Husqvarna 128LD air filter part number?
Husqvarna 530150253 is the air filter for the 128 LD and 128 CD, and it also fits the 128 L, 128 R, 125 L and 125 R. Husqvarna also sells a 128 series tune-up kit with a fuel filter, air filter and spark plug; the plug is a Champion QCJ-8Y (September 2023 manual).