Koso
Koso 4 Valve Cylinder Head
$969.13
The Koso 4V Head Kit is the ideal engine part to complete the Koso Honda Grom® Big Bore kit.
View product detailsIn stock
Saved catalog stock record Sep 19, 2026
- Manufacturer part #
- MC623000
Vehicle compatibility
Choose your vehicle to check this item's listed applications.
Choose your vehicle →Product description
The Koso 4V Head Kit is the ideal engine part to complete the Koso Honda Grom® Big Bore kit. Because of its unique 4 valve design, the air flow and performance are increased. This new designed head is the perfect addition for those who desire more power and torque. Not legal for use in California on pollution controlled vehicles, race use only in California - waiver available. Requires the use of Iridium spark plug The 4 Valve Head Kit features a forged piston, stainless steel 24 mm intake valves and 20 mm exhaust valves. Only fits Koso 170cc big bore kit.
Features
- Not legal for use in California on pollution controlled vehicles, race use only in California - waiver available.
- Requires the use of Iridium spark plug
- The 4 Valve Head Kit features a forged piston, stainless steel 24 mm intake valves and 20 mm exhaust valves. Only fits Koso 170cc big bore kit.
Specifications
- Product Type
- Engine
- Segment
- Street
- Sub Segment
- Mini Bike
Listed vehicle applications
16 vehicle applications for the selected item. Showing 12 examples. Use the vehicle selector for an exact check.
| Year | Make | Model / configuration |
|---|---|---|
| 2016 | Honda | MSX125 Grom |
| 2018 | Honda | MSX125 Grom |
| 2019 | Honda | Z125 Monkey |
| 2019 | Honda | MSX125 Grom |
| 2018 | Honda | MSX125A Grom ABS |
| 2019 | Honda | MSX125A Grom ABS |
| 2019 | Honda | Z125A Monkey ABS |
| 2020 | Honda | MSX125 Grom |
| 2020 | Honda | MSX125A Grom ABS |
| 2020 | Honda | Z125A Monkey ABS |
| 2020 | Honda | Z125 Monkey |
| 2021 | Honda | MSX125A Grom ABS |
What Our Customers Say
“Great place to buy from great parts great people”
“10/10 experience with Empire Cycle. Kristin and Joe are great to work with and very helpful. Will absolutely do business with them again.”
“I had a pleasant experience doing my business with these folks! I purchased a 2024 CF MOTO 450SS. They communicate with you well, care about what your needs are, and prioritize your satisfaction. I also took my another bike for mods. Austin and Amy do an amazing job! Thank you, everyone!!”
“Amazing people!! Helped me out with parts when I was in a pinch and they were very friendly. I would recommend anyone looking for moto supplies or new vehicles to stop in and see what they got.”
“Awesome people and great deal on gear! Outfitted the whole family and several friends with the insane Helmet deals. Keep it up 🙏”
“:) Thank you”