Stihl FS 38 Serial Number (Lookup Guide)
To identify an STIHL FS 38, find the model marking and the complete serial number stamped on the engine or crankcase area. Record every digit, including leading zeros, then ask an authorized STIHL dealer or STIHL customer-support channel to confirm the machine and the right manual or parts. Do not use the number alone to guess its year.
If you are trying to order a part, check a used trimmer, or confirm which manual applies, the serial number is useful only when read correctly and checked with STIHL. The FS 38 is a petrol line trimmer, not a chainsaw. Chainsaw guide-bar and chain details do not apply to it.
A buyer might ask, “The number is worn, and the seller says this part fits every FS 38. How can I check?” That is a sensible question. Model versions and market specifications can differ, and an online number pattern is not a reliable substitute for confirmation. Below is a careful way to identify the trimmer and use its serial number.
FS 38 Serial-Number Location and Safe Identification
The serial number is marked on the engine or crankcase area. Its exact position can vary, so check the operator’s manual for your version if you do not see it. Clean the area gently, use good light, and record the full marking before asking STIHL to identify the machine.
Step-by-step: find and record the number
- Make sure the trimmer is switched off and cool. Place it on a stable surface.
- Look around the engine and crankcase for a stamped or printed identification marking. Do not assume a sticker on a replacement part is the machine’s serial number.
- Wipe away loose dirt with a cloth. Avoid scraping the marking with a sharp tool, which may damage it.
- Find the model designation, “FS 38,” and the serial number. They are different pieces of information.
- Copy the serial number exactly, preserving leading zeros and any letters or spacing shown. Take a clear photo if the marking is hard to read.
A serial number is a unique identification marking for the machine. It is not a dependable public code for working out the model year. STIHL number formats have varied by age and market, so a guessed pattern may lead to the wrong conclusion.
| What you find | What to do | What not to assume |
|---|---|---|
| Clear FS 38 model marking and clear serial number | Record both, then contact STIHL or a dealer | That the digits reveal the year |
| Dirt over the number | Clean gently and photograph it in good light | That a partial number is enough |
| Worn or partly unreadable marking | Share a photo and any readable digits with a dealer | That a similar-looking number belongs to your unit |
| No visible number in the expected area | Check the manual or ask a dealer where to look on that version | That the number is missing or the machine is counterfeit |
If the marking remains unreadable, do not fill in missing digits by guesswork. A dealer may be able to advise what other details or photos are useful. Keep the trimmer’s model information and serial-number photo together for future parts or service questions.
Check a used FS 38 before you buy
A serial number can help a dealer identify a machine, but it does not prove by itself that a used trimmer is genuine, complete, or in good condition. Compare the marking on the machine with any paperwork the seller provides. Ask the seller to let you inspect the number and the machine before payment.
For a practical check, photograph the model marking, serial marking, engine area, guard, handle, and cutting head. If a seller will not let you inspect the machine or share basic identification details, treat that as a reason to pause. Ask a STIHL dealer to advise whether the number and model information can be checked.
Next step: Use a complete, legible number for a dealer inquiry. Do not decide the year, parts fit, or authenticity from an unofficial decoder.
Confirming Model Compatibility Before Ordering Parts
The serial number helps a STIHL dealer identify the machine and check which parts or manual apply. It does not make every part advertised for an FS 38 compatible with every version. Give the dealer the model and full serial number, then confirm the exact part before placing an order.
What information to give the dealer
When you call or visit, provide:
- The model designation as marked: FS 38.
- The complete serial number, including leading zeros.
- A clear photo of the identification marking if any digit is uncertain.
- The part name or a photo of the part you want to replace.
- The country or market where the trimmer was sold, if known.
Ask the dealer to confirm the machine identity and the applicable parts information or operator’s manual. If you are ordering online, compare the part number the dealer confirms with the seller’s listing. A listing that only says “fits FS 38” may not show whether it covers your exact version.
Common lookup situations
These are practical examples of how to handle typical questions; they are not claims about a particular customer or machine.
| Situation | Best next step | Reason |
|---|---|---|
| You need a manual | Give STIHL or a dealer the model and serial number | The correct documentation may depend on the machine version or market |
| You need a replacement part | Ask for a fit check using the full identification | Similar model names do not guarantee the same part |
| You are checking a used trimmer | Compare the machine’s markings and ask a dealer to review them | A number pattern alone cannot verify condition or authenticity |
| The serial number is partly worn | Send a photo and state which digits are uncertain | Guessing can point to the wrong machine |
| A seller says all FS 38 parts are the same | Request the exact part number and verify it with a dealer | Fit may vary by version |
A dealer’s confirmation is especially important when a part affects safety, such as the guard or cutting head. Do not rely on a marketplace title, a forum post, or an unofficial serial-number lookup as the final fit check.
The FS 38 is a 27.2 cm³, single-cylinder, two-stroke petrol line trimmer. Its standard configuration uses a nylon mowing head. A commonly specified line diameter is 2.0 mm, but check the manual and the head for your exact market and version before fitting line. These details can help frame a parts question; they do not replace the serial-number check.
Next step: Ask the dealer to confirm both the part and the applicable manual for your serial-numbered machine.
Routine Inspection, Line-Head Service, and Fueling
Before using the trimmer, check its guard, handle, mowing head, line, throttle control, and stop switch. Use only a cutting attachment approved for the exact FS 38 version and the correct guard. Follow the operator’s manual for line, fuel, and service instructions.
Check the cutting head and guard
Inspect the mowing head for cracks, heavy wear, or incorrect fit. Check that the guard is present, secure, and undamaged. A worn or incorrectly fitted head can break apart at operating speed and cause severe impact injuries. Do not run the trimmer if the head or guard is damaged.
Use the nylon mowing head specified for your version. Do not treat an FS 38 as a brushcutter approved for a metal blade unless the documentation for that exact machine explicitly permits that setup. Never fit an attachment just because it appears to connect.
Before starting, check that the line is the correct type and diameter for the head. The commonly specified FS 38 line diameter is 2.0 mm, but market and version details matter. If the head’s marking and the manual differ from a general online listing, ask a dealer before operating.
Mix fuel as directed
The FS 38 is a two-stroke machine. The specified fuel mix is 50:1 gasoline to two-stroke engine oil approved for air-cooled STIHL engines. Follow the machine’s manual and the oil label. Do not run straight gasoline, and do not estimate the ratio by eye.
Check the fuel container label and measure both parts of the mix carefully. If you are unsure what fuel is in the tank, do not start the trimmer until you have checked the manual or received advice from a dealer. Use the starting and fueling steps given in the operator’s manual for your version.
| Before operation | Check |
|---|---|
| Guard | Present, secure, and not damaged |
| Mowing head | Correct type, firmly fitted, and free of cracks |
| Nylon line | Correct specification for the head and version |
| Controls | Throttle and stop switch work as described in the manual |
| Fuel | Correct 50:1 mix using approved air-cooled two-stroke oil |
Next step: If any safety part is damaged, missing, or uncertain, do not operate the trimmer until it has been checked and corrected.
Long-Term Storage and Seasonal Care
For storage, use the instructions in the FS 38 operator’s manual that matches your machine. The right steps can depend on the version and the fuel guidance for the product you use. Keep the serial number and manual details with the trimmer so you can confirm parts or service information later.
Before putting the trimmer away, switch it off, let it cool, and inspect it for visible damage. Store it in a safe, dry place as directed by the manual. Follow the manual and fuel-container instructions for handling any remaining fuel; do not improvise a storage method.
When bringing the machine back into use, check the identification and safety items again. Look over the guard, handle, head, line, throttle, and stop switch. Confirm that the fuel is suitable and correctly mixed before starting.
A compact record helps if you need help later:
- Model: FS 38.
- Full serial number: copied exactly from the machine.
- Market or country of purchase, if known.
- Manual version or publication details, if shown.
- Parts or service questions already checked with a dealer.
Next step: Keep a photo of the serial marking and the dealer-confirmed parts information. That record makes later service questions easier and reduces the risk of ordering by model name alone.
FAQ: STIHL FS 38 Serial Number
These short answers cover the main identification and lookup questions. The key rule is to record the number as marked, then ask STIHL or an authorized dealer to confirm the machine, manual, or part. Do not rely on a guessed serial-number pattern for year or fit.
Where is the serial number on an STIHL FS 38?
Look on the engine or crankcase area. Position can vary, so check the manual for your version or ask a STIHL dealer if you cannot find it.
How do I read a dirty serial number?
Wipe it gently with a cloth and use good light. Photograph the marking if it remains difficult to read.
Should I include leading zeros?
Yes. Copy the complete serial number exactly as shown, including leading zeros and any letters or spacing.
Can I tell the FS 38’s year from its serial number?
Do not assume so. Number formats vary by age and market. Ask STIHL or a dealer to identify the machine.
Can I use an online serial-number decoder?
Do not rely on an unofficial decoder as confirmation. Give the model and full number to STIHL or an authorized dealer.
What should I provide when ordering parts?
Provide “FS 38,” the complete serial number, and the part you need. Ask the dealer to confirm the correct part for that exact machine.
Is the FS 38 a chainsaw?
No. It is a petrol line trimmer. Chainsaw bar and chain specifications do not apply.
What fuel mix does the FS 38 use?
The specified ratio is 50:1 gasoline to approved air-cooled STIHL two-stroke engine oil. Follow the manual and oil-label instructions.
What line diameter should I use?
A commonly specified diameter is 2.0 mm. Confirm the line and head requirements for your exact version and market.
Can I fit a metal blade?
Do not do so unless the documentation for your exact FS 38 explicitly permits it. Use the approved attachment and correct guard.
(This article was written by one of our staff writers, Elliott Fowler. Visit our Meet the Team page.)
