we revived the abandoned Yerfdog 3209!
parts we used are below if you're looking to rebuild the top end of your 157QMJ GY6 Engine. All links are NON affiliated, I paid for all these parts with my own money.
Glixal ATMT1-017 GY6 150cc 57.4mm Cylinder kit with Piston Kit 4 Stroke 152QMI 157QMJ TAOTAO JONWAY ZNEN Roketa ATV Moped Go-Kart https://a.co/d/0a7S8z9R
Glixal ATGT-018 GY6 125cc to 150cc 57.4mm Cylinder Head Asyy with Valves set for 152QMI 157QMJ Scooter Moped ATV Go Kart Quad Engine (Non EGR Type) https://a.co/d/0faWDf6W
Glixal ATKS-03905 High Performance Racing Moped ATV Scooter Torque Spring with Clutch Springs for GY6 125cc 150cc 157QMJ 152QMI Engine (1500RPM,Yellow) https://a.co/d/06sOLCky
Glixal ATMT1-101 GY6 125cc 150cc Scooter Moped Cam Shaft Timing Chain Tensioner for 152QMI 157QMJ ATV Quad Go Kart https://a.co/d/0eXnVj2x
Glixal 18x14mm High Performance Polygon Variator Sliders, Racing Sliding Roller Weights 152QMI 157QMJ GY6 125cc 150cc Scooter Moped ATV (12 Gram) https://a.co/d/07k5vmY8
Glixal GY6 125cc 150cc Rear Clutch Driven Pulley with Clutch Bell for 152QMI 157QMJ Scooter Moped ATV Go-Kart Engine https://a.co/d/00Se6nq2
Gates PL20707 PowerLink Continuously Variable Transmission (CVT) Scooter Belt https://a.co/d/0fEbij9z