Honda Engine Model Numbers Explained
html
Honda Engine Model Numbers Explained: What S, Q, V, H, L and X Mean
When ordering Honda engine parts, the model number alone is not always enough. Two engines can both be marked as GX160, GX200 or GX390, but still use different shafts, gearboxes or engine features.
The extra letters in the Honda engine type code help identify the exact version of the engine. This is important when matching parts such as carburettors, service kits, air filters, recoil starters, pulleys and replacement engines.
Model Number, Type Code and Serial Number
A Honda small engine usually has three useful identifiers:
- Model number - the base engine model, such as GX160, GX200, GCV160 or GX390.
- Type code - the letter and number code that identifies the exact engine version.
- Serial number - the individual engine number, usually stamped near the type code.
The model number starts with the letter G and is usually found on a sticker on the engine cover or recoil housing. The engine type code and serial number are normally stamped into the side of the engine.
What Common Honda Type Code Letters Mean
The type code is the part that often confirms the shaft size, gearbox setup or extra engine features. Common Honda small engine code letters include:
| Code | Common Meaning |
|---|---|
| S | 20mm straight shaft |
| Q | 3/4 inch straight shaft |
| V | Tapered shaft |
| H | 6:1 reduction gearbox |
| L | 2:1 reduction gearbox |
| X | Oil Alert |
For example, a GX160 with an S type code is not the same as a GX160 with a Q type code. The engine model may be the same, but the shaft size is different.
Why S and Q Shafts Are Easy to Mix Up
The S and Q codes are one of the most common areas for mistakes. An S shaft is 20mm. A Q shaft is 3/4 inch, which is around 19.05mm.
That difference looks small, but it matters. Pulleys, couplings, sprockets and driven parts may not fit correctly if the wrong shaft type is ordered.
What Details Should You Send When Asking for Parts?
To help match the correct Honda engine parts, send as much information as possible:
- The engine model, such as GX160 or GX200
- The full type code
- The serial number
- A clear photo of the engine and stamped numbers
- The machine make and model, if known
This helps avoid ordering parts that look right but do not fit your exact Honda engine version.
Honda Engine Code FAQs
Is GX160 enough to order parts?
Not always. GX160 tells you the engine family, but the type code helps confirm the exact version.
Where is the Honda engine type code?
It is usually stamped into the side of the engine, close to the serial number.
What does Q mean on a Honda engine?
Q commonly means a 3/4 inch straight shaft.
What does S mean on a Honda engine?
S commonly means a 20mm straight shaft.
Are 20mm and 3/4 inch shafts the same?
No. A 3/4 inch shaft is around 19.05mm, so it is close to 20mm but not the same.
What does X mean on a Honda engine code?
X commonly refers to Oil Alert on Honda small engine type codes. Always check the full type code before ordering parts.
Need Honda Engine Parts?
If you are not sure which Honda engine you have, send us the model number, type code, serial number and a clear photo. We can help identify the correct parts for your engine.
Browse Honda Engine Spares Open a Trade Account
