VHM Top End Gasket Kit for HUSQVARNA TC 125, KTM SX 125 and GAS GAS MC 125 2016-2025

The VHM SK33156 top end gasket kit is designed for KTM SX 125, HUSQVARNA TC 125 and GAS GAS MC 125 from 2016 to 2025. The top end gasket kit brings together the gaskets to replace every time the cylinder head or cylinder comes off. A gasket crushed by tightening never gets its shape back: refitting it means risking a compression, coolant or oil leak, and having to strip everything down again.

Specifications

• Brand: VHM
• Manufacturer part number: SK33156

When to replace it?

• Coolant or oil seeping at the head/cylinder or cylinder/crankcase joint.
• Coolant level dropping, bubbles in the radiator.
• Hissing or black marks where the exhaust leaves the cylinder.

At every piston change and every time the cylinder head or cylinder is removed, even for a simple inspection. Gaskets cost little compared with the work of stripping the engine.

Fitting tips

1. Clean the gasket faces without scratching them (plastic scraper, solvent): they must be clean, dry and free of burrs.
2. Fit the gaskets dry, without sealant, unless the workshop manual says otherwise.
3. Refit a base gasket of the same thickness as the old one, unless you are deliberately adjusting the squish.
4. Tighten the cylinder head in a criss-cross pattern, in several stages, up to the manufacturer's torque.
5. While it's apart, replace the spark plug and refill the coolant.
6. After break-in, check the torque with the engine cold and make sure there are no leaks.

Why VHM?

Since 1995, VHM has been designing racing engine parts for two-strokes: cylinder heads with interchangeable inserts, combustion chamber inserts, crankshafts and connecting rods. A specialist brand, used to fine-tune an engine's power without transforming it.

Spare parts and items to plan

• Piston : VERTEX 24243A · VERTEX 24419A
• Piston rings : PROX 02.6225 · PROX 02.6220
• Spark plug : NGK 2707 · NGK 3230
• Coolant : LIQUI MOLY 1 L · TWIN AIR
• 2-stroke oil : LIQUI MOLY 1 L 3065 · LIQUI MOLY 1 L 3063

Frequently asked questions

What does the kit contain?
Depends on the model. Compare with your original gaskets if in doubt.

Should I replace it along with the piston?
Yes: as soon as the cylinder head and cylinder are off, new gaskets go back on. It's the right time to fit a new piston kit and new rings if the engine has some hours on it.

Compatibility

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

Fits:
GAS GAS MC 125 2025
GAS GAS MC 125 2024
GAS GAS MC 125 2023
GAS GAS MC 125 2022
GAS GAS MC 125 2021
HUSQVARNA TC 125 2025
HUSQVARNA TC 125 2024
HUSQVARNA TC 125 2023
HUSQVARNA TC 125 2022
HUSQVARNA TC 125 2021
HUSQVARNA TC 125 2020
HUSQVARNA TC 125 2019
HUSQVARNA TC 125 2018
HUSQVARNA TC 125 2017
HUSQVARNA TC 125 2016
KTM SX 125 2025
KTM SX 125 2024
KTM SX 125 2023
KTM SX 125 2022
KTM SX 125 2021
KTM SX 125 2020
KTM SX 125 2019
KTM SX 125 2018
KTM SX 125 2017
KTM SX 125 2016