VHM Cylinder Head for BETA RR 300, RX 300, XTRAINER 300 2013-2025

The VHM AA33182 cylinder head is designed for BETA RR 300, RX 300, XTRAINER 300 from 2013 to 2025. 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: AA33182
• 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 : PROX 36.7323 · PROX 35.7323
• Spark plug : NGK 95476 · NGK 5122
• 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:
BETA RR 300 2024
BETA RR 300 2023
BETA RR 300 2022
BETA RR 300 2021
BETA RR 300 2020
BETA RR 300 2019
BETA RR 300 2018
BETA RR 300 2017
BETA RR 300 2016
BETA RR 300 2015
BETA RR 300 2014
BETA RR 300 2013
BETA RX 300 2025
BETA RX 300 2024
BETA RX 300 2023
BETA XTRAINER 300 2025
BETA XTRAINER 300 2024
BETA XTRAINER 300 2023
BETA XTRAINER 300 2022
BETA XTRAINER 300 2021
BETA XTRAINER 300 2020
BETA XTRAINER 300 2019