Koso 4-Valve Head 170cc Big Bore Kit MB623003 for Honda Grom Monkey 2014-2021

Important: Must use 91-94 octane Premium gas.
To run correctly you will also need a high flow injector, injector adaptor, racing filter, connecting tube, intake tube, 34mm throttle body, high flow oil pump, iridium spark plug, ECU modification, fuel tuner, and performance exhaust.
See description for a list of additional parts from Koso

Specifications
Cylinder Height:	64.2 mm
Head Gasket Thickness:	0.25 mm
Base Gasket Thickness:	0.5 mm
Total Volume:	169.21 cc
Squish:	1 mm
Cylinder Head Volume:	13.4 cc
Compression Ratio:	12.3:1
Valve / Tappet Clearance:	Intake: 0.10 mm; Exhaust: 0.17 mm
Intake Valve Size:	24 mm
Exhaust Valve Size:	20 mm
Features:	Ceramic coated cylinder; Forged piston; 4-Valve head
Notes:	Requires Iridium spark plug (not included)

Required additional components (Sold separately)
Description	Partnumber
High flow injector	DB008160
Injector Adaptor	DB623000
Racing filter (Grom only)	DK623000
Racing filter (Monkey only)	DK633000
Connecting tube (Grom only)	DM623000
Intake tube (Grom only)	DM623K10
34mm Throttle body	DY623013
High flow oil pump	NF623000
Iridium spark plug ER9EHIX	-----
ECU Modification	-----
Fuel Tuner	-----
Performance Exhaust	-----

Product Features

• Take your Grom/Monkey to the next level with Koso's 170cc big bore kit with 4-Valve cylinder head
• The kit features 24mm intakes valves, 20mm exhaust valves, a specially designed forged piston, and a ceramic coated cylinder

Fits:

Make	Model	Year
Honda	Grom 125	2014-2015
Honda	Grom 125	2017-2021
Honda	Grom 125 ABS	2018-2021
Honda	Monkey Z125M	2019-2021
Honda	Monkey Z125MA ABS	2019-2021