TSP Head insert – suits TSP Billet Head for Yamaha YZ125 05-21 & YZ125X 05-22

This listing is for the insert only, it does not include the head cap!

This is the listing to buy additional/replacement compression inserts to suit your TSP YZ125 head cap. This will not fit without a TSP head cap.

YZ125 2005-2021 – See the listing for our 2022 model.

YZ125X 2020-2022

This insert will come with the inner o-ring required & O-ring kit

Medium Compression: This design offers a similar compression ratio to the stock head, but with a much better design. Squish clearance is tighter than stock and the design is much more detonation resistant than the stock head. It offers improved power throughout the rev range and makes a great bike even better. It is best suited to high level MX riding or very fast riders who like to rev the engine hard.

High Compression: This design is slightly higher compression than the stock head but still safe for 98 RON pump fuel with appropriate jetting. It offers improved bottom/mid power over the Mid/High design and is best suited to trail riding, offroad racing or MX riders who want max midrange pull. It is also recommended for the YZ125X model and gives very linear, strong power delivery when the standard YZ125 model powervalve spring is used (we can supply this if necessary).

Additional information