VHM Cylinder Head for KTM EXC 250, XC 250, XCW 250, HUSQVARNA TE 250 and GAS GAS EC 250 2018-2023

The VHM AA33175 cylinder head is designed for KTM EXC 250, XC 250, XCW 250, HUSQVARNA TE 250 and GAS GAS EC 250 from 2018 to 2023. The cylinder head closes off the top of the cylinder and forms the combustion chamber. On a two-piece VHM head, the chamber is a machined insert that can be swapped in a few minutes to adapt the engine's compression.

Key features

• Two-piece cylinder head: body and interchangeable combustion chamber insert.
• Compression adjustable by swapping the insert, without removing the cylinder.

Specifications

• Brand: VHM
• Manufacturer part number: AA33175
• Engine: 2-stroke

Who is it for?

• Original head damaged by pinking (detonation), cracked or warped.
• You want to match the compression to the fuel, the terrain or a tuned engine.
• You're after a smoother or snappier engine without changing the cylinder.

Good to know

The insert is chosen to suit your engine and your fuel: a smaller chamber volume raises compression, which may call for a higher-octane fuel. Always check the squish when fitting.

Fitting tips

1. Clean the cylinder mating face without scratching it.
2. Fit new O-rings and grease them lightly so they stay in place.
3. Check the squish (gap between piston and head) with solder wire before riding.
4. Tighten the head in a criss-cross pattern, in several stages, to the recommended torque.
5. Fit a new spark plug and refill the coolant.

Why VHM?

Founded in 1995, VHM specialises in racing engine parts for motocross, road racing and karting. The brand started out with cylinder heads featuring interchangeable combustion chambers, which became its speciality, and then developed crankshafts, connecting rods and gasket kits.

Spare parts and items to plan

• Top-end gasket kit : ATHENA M752007300094 · ATHENA M752010500094
• Spark plug : NGK 6664 · NGK 6615
• Coolant : LIQUI MOLY 1 L · TWIN AIR

Frequently asked questions

Can I change the compression later?
Yes: just swap the VHM insert, without removing the cylinder.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
GAS GAS EC 250 2023
GAS GAS EC 250 2022
GAS GAS EC 250 2021
HUSQVARNA TE 250 2023
HUSQVARNA TE 250 2022
HUSQVARNA TE 250 2021
HUSQVARNA TE 250 2020
HUSQVARNA TE 250 2019
HUSQVARNA TE 250 2018
KTM EXC 250 2023
KTM EXC 250 2022
KTM EXC 250 2021
KTM EXC 250 2020
KTM EXC 250 2019
KTM EXC 250 2018
KTM XC 250 2023
KTM XC 250 2022
KTM XC 250 2021
KTM XC 250 2020
KTM XCW 250 2023
KTM XCW 250 2022
KTM XCW 250 2021
KTM XCW 250 2020
KTM XCW 250 2019