NONE!! THESE ARE ALL TRASH!! You coulde build a MUCH better engine for less then $300.

Bottom End $65 https://www.californiamotorbikes.com/product-page/80cc-wildcat-bottom-end

Ported Cylinder $35 https://www.californiamotorbikes.com/product-page/gtz-ultra-racing-cylinder-fully-ported-for-reed-for-80cc-two-stroke

Piston $15 https://www.californiamotorbikes.com/product-page/replacement-80-66cc-piston-and-rings-set-for-two-strokes

G2 Reed $20 https://www.amazon.com/Miaowa-Racing-Intake-Motorized-Bicycle/dp/B098X32Y9P/ref=sr_1_7?crid=1SM5JFCRVYPIY&keywords=motorized+bike+g2+reed&qid=1666013801&qu=eyJxc2MiOiIwLjAwIiwicXNhIjoiMC4wMCIsInFzcCI6IjAuMDAifQ%3D%3D&sprefix=motorized+bike+g2+reed%2Caps%2C83&sr=8-7

G2 Reed OKO Intake $40 https://dlh-performance.myshopify.com/products/32mm-intake-g2-reed

21mm OKO $25 https://www.amazon.com/Carburetor-Motorcycle-Racing-Universal-Scooters/dp/B09ZP7YZJ3/ref=sr_1_18?crid=3O1T6XCAOIEQ2&keywords=21mm%2BOKO%2Bcarburetor&qid=1666015057&qu=eyJxc2MiOiIzLjQ2IiwicXNhIjoiMy4zMyIsInFzcCI6IjEuOTIifQ%3D%3D&sprefix=21mm%2Boko%2Bcarburetor%2Caps%2C79&sr=8-18&th=1

Performance Head $35 https://www.amazon.com/CDHPOWER-Performance-Head-Stroke-Engine/dp/B06Y64K3GL/ref=sr_1_9?crid=3SY899Z7DS32C&keywords=motorized+bike+high+compression+head&qid=1666115840&qu=eyJxc2MiOiIzLjU5IiwicXNhIjoiMy4xMCIsInFzcCI6IjIuNTAifQ%3D%3D&sprefix=motorized+bike+head%2Caps%2C88&sr=8-9#customerReviews

Magneto $15 https://www.californiamotorbikes.com/product-page/high-performance-magneto-extra-winding

Spark Plug $5

https://www.amazon.com/NGK-BR6HS-Standard-Spark-Plug/dp/B000F0G0TK/ref=sr_1_5?crid=DTPNV9M6E3HX&keywords=NGK+Br6hs&qid=1667309787&qu=eyJxc2MiOiIzLjQ5IiwicXNhIjoiMy4wNSIsInFzcCI6IjIuOTEifQ%3D%3D&s=automotive&sprefix=ngk+br6hs%2Cautomotive%2C108&sr=1-5

Air Filter $10 https://www.amazon.com/dp/B09TGRYZ48/?coliid=I2G465IZS3FFB1&colid=3NPEDI9LTMICE&ref_=lv_ov_lig_dp_it&th=1

Mz65 Exhaust $35 https://www.amazon.com/dp/B07ZPMTX47/ref=twister_B0833SJDSF?_encoding=UTF8&th=1

NONE!! THESE ARE ALL TRASH!! You could build a MUCH better engine for less than $300.