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Hop Up Kit - GX200 & 6.5 Chinese OHV, Stage 4
Hop Up Kit - GX200 & 6.5 Chinese OHV, Stage 4

Our Price: $639.99

Stock Status:In Stock

Choose Engine Type

Yellow, Red, & Most 6.5 OHV Engines
GX200 [+$30]
GX160 [+$30]
Select Valve & Spring Combination

27mm Intake, 24mm Exhaust, 37 lb Springs, Aluminum Retainers
27mm Intake, 25mm Exhaust, Dual Springs, Aluminum Retainers [+$35]
28mm Intake, 25mm Exhaust, Dual Springs, Aluminum Retainers [+$70]
28mm Intake, 25mm Exhaust, Dual Springs, Titanium Retainers [+$85]
32mm Intake, 28mm Exhaust, Dual Springs, Aluminum Retainers [+$105]
32mm Intake, 28mm Exhaust, Dual Springs, Titanium Retainers [+$120]
Select Piston/Rings

Honda UT2 Flat-top and 3.403 Long Rod [+$48]
Wiseco Forged, 2-Ring (adds long rod) [+$106]
Wiseco Forged, 3-Ring (adds long rod) [+$112]
Select Carburator

22mm Mikuni - Gas
28mm Flat Slide Mikuni - Methanol [+$106]
28mm Gas Black Round Slide [+$65]
24mm Flat Slide Mikuni - Gas [+$79]
Select Compression Ratio

10.5 to 1
11 to 1
12 to 1
13 to 1
Crankshaft Type/Options

No Crankshaft
.060 Stroker, Honda Core, Balanced [+$267]
.060 Stroker Crankshaft, Aftermarket (Chinese) Core, Balanced [+$218]
.175 Billet Stroker (includes Wiseco Piston) [+$495]
Select Camshaft

252 0207 (very small oval 6500 rpm)
252 0611 (road Courses)
274 0207 (small Oval, 7500 rpm)
274 0607 (large oval 8000+ rpm)
274 1007 (1/4 mile tracks, 9500 Rpm)
280 0611 (Snow Mobile, Mini Bikes)
307 0807 (Drag Race Only)
Select Flywheel

No Flywheel
Small Diameter Flywheel, Adjustable THE BEST!! [+$187]
Super Light, ARC 6602 & Small Fan (use stock key) [+$113]
Lightweight Billet Aluminum w/PVL Digital Ignition System [+$246]
Additional Options

Add Roller Rockers (spacer included) [+$136]

Description -

Our Stage 4+ kits allows you to customize a kit for your application. The 4+ kit starts with package similar to that of the stage 3 kit but adds a Ported and Milled Head, stainless valves, billet rockers, and a serious cam package. Options include everything from roller rockers to stroker kits. This kit will allow you to build a motor in excess of 20+ hp.


  • Race/Open Air Filter & Adapter,
  • 22mm Mikuni Carb Kit (other carbs optional)
  • Ported & Milled Chinese OHV Head
  • 1.2 Billet Rocker Arms
  • Chrome Moly Pushrods
  • Stud Kit
  • 26 lb Springs,
  • Lash Caps
  • Offset Timing Key (not with all flywheels)
  • Gasket Kit
  • Billet Rod (not shown in picture), std with Chinese OHVs, .020 with GX200s
  • Billet Guide plate
  • Choice of Compression Ratios - Compression ratios based on Flat-Top piston. If a Dished piston is used, deduct approx 1.5 points,
  • Choice of Cams
  • Optional Long Rod
  • Optional Roller Rockers
  • Optional Flywheels
  • Optional Crankshaft
  • Optional Stroker Kit
Honda Kits use genuine Honda 18cc Heads, Clone Kits use 22cc Clone Heads (Honda kits will fit Clone if 18cc head is desired)

Picture is for reference only!!! Actual content based on above description and selections. In otherwords, the flywheel shown is optional!!
Due to the head work involved in these kits, Allow 1 week to ship

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

Note: This kit will not fit Harbor Freight 212 (predator) engines. Please see our Predator Kits for those applications

These kits are intended for experienced engine builders. Some clearancing, fitment, or other engine building "tricks" may be needed.

Aluminum flywheel recommended. Stock flywheels are prone to failure and very DANGEROUS

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