STM Polaris PRO R STM Tuner Secondary 4 Cylinder Engines

The secondary features all billet construction and is capable of using compression or torsion springs with different spring rates available.

This clutch uses our Gen 1 ATV style helixes.

The clutch fits under the stock clutch housing and works with the stock primary or the STM primary. Best results are acquired when running both the STM primary and STM tuner together.

Includes a new hub insert for use with the stock bolt, and an adjuster nut tool to change the belt and set the belt tension

Choose a helix angle - The most popular helix for stock machines is the 50/40 It is a good all-around helix.

Choose a spring– The most popular spring is the KSS8 lime green. This spring works well for stock tires.

KEEP IN MIND WE CAN ONLY GET YOU CLOSE WITH SET-UP. Everyone's riding style is different so it’s up to the customer to do the fine tuning!