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Hygge Performance



Regular price $398.00 USD
Regular price Sale price $398.00 USD
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**Due to the many color/dome and engraving options Phatheads are a special order item - Please email before ordering if you are in a rush**

Do you want...
More consistent jetting
More power
More fuel efficiency

What’s included:
1 BADA$$ billet PhatHead cylinder
Dome of your choice for multiple compression ratios
Set of dome O-rings
New nuts and crush washers (where applicable)

**Please contact us at for big bore options**

Are you tired of...
Inconsistent jetting? Poor fuel economy? Low power? How about poor throttle response or detonation? Maybe your bike already runs good, but you know it can be even better. What if I told you that with a PhatHead for YZ125 your bike could run cleaner, makes more power, and burns less fuel?

Tighten up that squish
Most bikes have an excessive amount of squish clearance from the factory. Squish clearance is the distance measured between the flat band on the cylinder head and the piston at TDC. Excess fuel trapped in an excessively wide squish band cannot be burned. This is reduces power, causes inconsistent jetting and poor fuel mileage.

Run cooler
By optimizing cylinder combustion efficiency and perfecting coolant flow PhatHead for YZ125 offers increased cooling over OEM heads.

More power
OEM bikes tend to come with low compression ratio’s to accommodate many different geographical regions , elevation and fuels (some poor quality). By bumping up the compression (even slightly) you can increase performance significantly throughout the power range. If you ride at higher elevation and are running stock compression, you will have less power then stock. This can easily be corrected by raising the compression to compensate for the lower air density. Keep in mind that raising compression in some cases may require higher octane fuel. This will depend on the application, elevation and engine modifications. If you are unsure what is best for your bike, please contact us at

Better fuel economy
How you may ask? Most bikes waste fuel through poor combustion. Unburned fuel from excessive squish clearance causing inconsistent, and poor jetting. Riders experiencing detonation tend to run there jetting on the rich side to compensate, reducing responsiveness and power even further. Tightening the squish and correcting the squish angle reduces wasted fuel and increases burn efficiency in the combustion chamber. With the burn corrected, now the jetting can be dialed in. Combine a more efficient burn with correct jetting and you get a longer fuel range and more power. WIN WIN!

PhatHead Kits include all required parts to complete installation.

**Based on a typical bike from the factory. Results may vary based on model and current set up.

Pair the PhatHead with a HYGGE chamber for ultimate performance upgrades! 

See a phathead installed on the bike



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