Hop Up Kit; GX340 to GX390, 420 Predator, & 13/15hp OHV; Stage 1

Stage 1 Hop Up Kit for GX340-GX390, 420 Predator, and 13/15hp OHV
Basic kit for improving the performance of GX390s, 420 Predators, 440 Duromax, and 13/15hp (440-460cc) Chinese OHVs. Simple to install, you can expect significant performance increases!

Kit Includes:

Race/Open Air Filter & Adapter
Heavy Duty Valve Springs
Offset Timing Key
Jet for Application (*see notes below*)
Optional Ignition Coil
Optional Twister Camshaft
Optional Header/Exhaust

*Note: UT2 series Hondas (2012 & up) have rev limited coils and will require a new coil to exceed 4000rpm. The UT2 coils (4 wire) can only be used with stock flywheels or 6693 ARC flywheels. If using any other flywheels, you must run a UT1 style coil (single wire). Most 390 “Clone”, 420s, and 460s have UT1 style coils already (however, some Lifans and 420s have a rev-limited digital ignition).

The correct jets must be selected for the application. If unsure, we recommend you check your STOCK main. If stock main is a:

#92-97, use a UT1 kit
#98-102, use a hemi kit
>102, use a UT2 kit

Manufacturers have been known to use different jets on the same models, so it is important to know the stock jet size!

*Picture is for reference only and may show optional parts. See above description for actual content. Header not included unless specified.
Filter should be sprayed with a K&N type oil, especially in dirt applications. Oil not included - click here.