Find your engine or saw tag (and the number that matters)

by Performance Saw Supply October 30, 2026

Most wrong-part returns start with the same mistake: ordering by the model name on the hood instead of the numbers on the engine tag. Two engines with the same name can have different bores, pistons and rings. Take a photo of the tag before you order. It is the fastest way to get the right part the first time.

Kohler

Command and Command Pro (CH, CV, SV, LH): the identification decal is on the engine shrouding. It lists the Model (for example CH25), the Spec number (for example CH730-0001 or 62500) and the Serial number. The spec number is the one that decides the bore and piston, so write it down. Kohler itself asks for all three when ordering parts.

KT17, KT19, M18, M20, MV16–MV20 and the K-series singles: look for the tag on the blower housing or shroud with the model, spec and serial numbers.

Briggs & Stratton

The model, type and code numbers are stamped into the engine, not printed on a sticker. Check the blower housing, the muffler heat shield, the area just above the spark plug, and on overhead-valve engines the rocker cover. A Briggs number looks like 33R777 0003 G1: model, then type, then code. Ignore the emissions label; it does not identify the engine.

Onan

The nameplate shows the model and a spec letter. The letter matters: on the B43, B48 and P216–P220 twins, earlier specs and later specs take different ring sets. Count the head bolts too. Nine head bolts and ten head bolts are different engine families.

Kawasaki

The model (for example FH381V, FR651V or FX730V) is on a label on the blower housing or near the air cleaner. Note the full model and any suffix; pistons and rings change between versions.

Chainsaws, trimmers and blowers

Stihl: the model is on the starter cover or top cover. Some models came in more than one bore, so measure if you are not sure.
Husqvarna: check the sticker on the underside or starter side. On the 150BT and 350BT blowers, the origin decal tells you which piston fits: Made in USA is pre-2021, Made in China is 2021 and later.
Echo: look for the sticker on the engine shroud or shaft. Similar names can take different pistons. The PB-251 and the PB-250/252, for example, are not the same.

No tag left?

Measure the bore and the old piston (see our guide on measuring before you order), look for part numbers cast into the old parts, and send us a photo. We will help you match it.