For building a serious a GX270 or 301, the 4 kit starts with package similar to that of the stage 3 kit but adds a Ported and Milled Head with stainless, stainless valves, stud kit, & HD valve train components.

Includes:

• Race/Open Air Filter & Adapter,
• Choice of Carbs
• Choice of Cams
• Fully ported and milled race head
• Stainless steel oversize vavles
• Fully ported and milled race head
• Chrome Moly Pushrods
• HD Single or Dual Springs
• 8 degree Timing Key
• Billet Rod
• Carb, Head, & Case gaskets
• Stud Kit
• Optional Roller Rockers
• Optional Header/Exhaust
• Reinforced Rocker Arms

Picture for reference only and may show optional parts. See above description for actual content. Header not included unless specified.

Note: Use of the Choke Bracket requires use of a stock Honda (or Chinese OHV) "Air Filter to Carb Gasket". This is not included in the kit. You can use the one that came with the motor, or can purchase one at

http://www.nrracing.com/product-p/16220-za0-702.htm

Picture for reference only and may show optional parts. See above description for actual content. Header not included unless specified.

Filter should be sprayed with K&N type oil, especially in dirt applications. Oil not included click here

Billet Aluminum flywheel recommended. Stock flywheels, esp "Clone" are prone to failure and very DANGEROUS

Note: UT2s series Hondas (2012 & up) or later have a built in Rev Limiter in the coil and will require a new coil to exceed 4000 rpm. The UT2 coils (4 wire) can only be used with stock flywheels. If using a Billet Flywheel, you must run a UT1 style coil (single wire).

Chinese Engines usually have UT1 style coils already. However some Lifans and 420s have a digital ignition and will need a Honda UT1 coil to run the billet flywheel.

If ordering for a 301, be aware some engines have large Cam Journals (.6357), most 301s have standard cam journals (same as GX270s). If you have a 301, we recommend you measure your cam journals before ordering this. (if in doubt, order the small journal).