VHM 28.50cc Cylinder Head Insert for KTM 300 EXC & Husqvarna TE 300

The VHM AE32274-F 28.50cc cylinder head insert is designed for selected KTM 300 EXC and Husqvarna TE 300 2-stroke applications using VHM cylinder heads AA33167 and AA33172.

For the AA33172 TPI platform, VHM specifies AE32274-F as the standard combustion chamber, including KTM 300 EXC TPI and Husqvarna TE 300i applications. VHM lists the chamber at 28.50cc, with 0.00 mm piston height and 1.90 mm squish.

Compared with the smaller-volume 27.50cc configuration, the larger 28.50cc combustion chamber reduces compression and shifts engine behavior toward better over-rev characteristics and stronger top-end performance. This makes the setup particularly suitable for hard ground, faster enduro terrain, and riding conditions where maintaining rpm is more important than maximum bottom-end response.

The trade-off of the larger-volume chamber is a softer low-rpm power reaction compared with smaller, higher-compression inserts.

The AE32274-F features a 28.50cc combustion chamber volume, 0.00 mm piston height, 1.90 mm squish, a flat-top chamber profile, and a Ø72 mm bore.

VHM’s interchangeable combustion chamber system allows the insert to be replaced without changing the complete cylinder head, making it easier to adapt engine characteristics to different terrain and performance requirements.

The AE32274-F also offers good resistance to detonation and features an engraved part-number reference for easy identification during engine servicing and setup.

This insert does not fit an OEM cylinder head and must be used with the appropriate VHM cylinder head.

Key Features

• 28.50cc VHM standard combustion chamber for AA33172-equipped 300 EXC TPI and TE 300i models
• Larger chamber volume promotes improved over-rev and stronger top-end performance
• Well suited to hard ground, faster enduro terrain, and high-rpm riding conditions
• Good resistance to detonation supports consistent performance under demanding use
• Quick-change VHM insert design allows easy servicing and combustion chamber adjustment

Technical Specifications