Engine upgrade kit for GY6 4-stroke scooters offering a jump to 180cc with a 61mm big-bore cylinder and a full rebuild parts set. Riders seeking stronger acceleration and better hill performance will notice the change during everyday use. Is the machining and installation effort worthwhile for most owners, especially workshops and DIYers? TRKIMAL GY6 Engine Upgrade Kit
⚡ At a Glance
- • Performance Gain: Increased bore from 57.4mm to 61mm raises displacement and torque
- • Best for: Owners and workshops upgrading GY6 125cc/150cc scooters, ATVs and go-karts
- • Not ideal for: Riders who cannot or will not arrange crankcase machining
Big-bore cylinder and full top-end parts convert many GY6 engines toward 180cc. Outer cylinder diameter requires crankcase boring to fit on most bikes.
Stronger acceleration and higher top speed – Thanks to 61mm bore upgrade
Larger bore increases cylinder capacity by moving from the stock 57.4mm toward a 61mm bore, raising overall displacement toward 180cc and allowing more air-fuel mixture per combustion cycle.
More usable mid-range torque improves overtakes and hill climbs, with crisper throttle response during normal riding.
Complete overhaul ready – With cylinder head, piston assembly and gaskets included
Includes a cylinder head assembly with valves, a 61mm cylinder block, a set of 61mm piston assembly (piston, rings and wrist pin) and gaskets, covering the main top-end components.
Maintenance shops and competent DIY mechanics can carry out a full top-end rebuild without sourcing multiple separate parts, cutting downtime.
Workshop-friendly upgrade – With a larger outer cylinder that needs machining
Outer cylinder diameter is 63.8mm, larger than the normal 61mm outer size on many stock GY6 heads, so the crankcase must be bored out for proper fitment on most bikes.
Well suited to owners who can arrange machine work; expect added labour for a correct, long-lasting installation.
✨ The 4 Key Reasons for TRKIMAL GY6 Engine Upgrade Kit
- 61mm Bore Upgrade – Noticeable increase in displacement and mid-range torque during everyday riding
- Complete Piston and Ring Assembly – Ensures reliable sealing and restores compression quickly after installation
- Cylinder Head with Valves Included – Saves sourcing time and supports improved engine breathing
- 63.8mm Outer Cylinder Size – Requires machining of crankcase for fitting on most bikes
📋 Technical Details at a Glance
- Category: Automotive Parts and Accessories
- Product Type: GY6 Engine Upgrade Kit
- Brand: TRKIMAL
- Compatible Engines: GY6 4-stroke 125cc/150cc
- Cylinder Bore: 61mm (upgrade from 57.4mm)
❓ Frequently Asked Questions
Q: Will the kit fit my GY6 125cc or 150cc engine without modifications?
A: No. The outer cylinder diameter is 63.8mm, so the crankcase must be bored out for fitment on most bikes and will require machine-shop work.
Q: What parts are included in the package?
A: Cylinder head assembly with valves, a 61mm cylinder block, a set of 61mm piston assembly (piston, rings and wrist pin) and gaskets are included.
Q: Can I use this on an ATV or go-kart with a GY6 engine?
A: Yes. The kit applies to GY6 4-stroke 125cc/150cc engines commonly found in many Chinese scooters, ATVs and go-karts, although fitting may still require machining.
🏆 Our Verdict
The TRKIMAL GY6 Engine Upgrade Kit is suitable for riders and workshops wanting a substantial top-end rebuild and a measurable power increase on GY6 125cc/150cc engines. Full head, piston and gasket set combined with a 61mm big-bore cylinder is the main selling point. While fitting requires crankcase machining, the upgrade delivers durable, usable performance gains that justify the installation effort over time.
