2019-2026 Yamaha YZ250F DEF Racing Stage 3 Cylinder Head Port *Labor Only*

Description The DEF Racing Stage 3 Cylinder Head Porting Service for the 2019-2026 Yamaha YZ250F was developed to maximize horsepower, torque and combustion efficiency through the entire power curve. Utilizing a high-precision airflow bench and advanced CNC technology, we reshape intake and exhaust ports as well as a major cleanup of the chamber face to improve combustion efficiency and airflow. Turn-Around Time Estimated 3-5 weeks from the date we receive the head Service Overview Teardown, cleaning & vapor blasting Thorough inspection of cylinder head Remove OEM original seats and guides & install our Moldstar90 seats and Moldstar22 valve guides CNC Port w/hand finish of the walls and combustion chamber face Final valve seat profile applied on a CNC machine Deck cylinder head to target combustion chamber volume and increasing compression Port Design Optimized exhaust and intake flow and velocity Power gains across all RPMs, with significant improvements in the mid to high RPM range Epoxied intake port improves engine torque and response OEM intake manifold spigot is port-matched for optimal performance Valve Seats and Valve Guides CNC machined valve seat profiles Valve seats are upgraded to Moldstar90 Valve guides are upgraded to Moldstar22 Pressure testing for leak detection Increased durability and performance Enhanced heat transfer improves performance and durability Customer Instructions Purchase the cylinder head service Send cylinder head & intake manifold to our shop (You are responsible for shipping to us) Place a copy of purchase order form in with your cylinder head Make sure all your contact details are in the box! We will call you when we receive your head to answer any questions and provide a more accurate lead time Return shipping cost is already included, and we will handle the logistics for returning to you. NOTE: Cylinder head port service does not include any valve train parts! Related