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Hop Up Kit - GX200, 6.5 Chinese OHV's, Stage 4
Hop Up Kit - GX200, 6.5 Chinese OHV's, Stage 4

Our Price: $619.99

Stock Status:In Stock

Choose Engine Type

Yellow, Red, & Most 6.5 OHV Engines
Blue (Lifan) 5-bolt Engines
GX200 (+$30)
GX160 (+$30)
Select Piston/Rings

T3 Dished, Genuine Honda (1.0mm Rings) [+$43]
T3 Flattop, Genuine Honda (1.0mm Rings) [+$45]
Honda UT2 Flat-top and 3.403 Long Rod [+$70]
Wiseco Forged, 2-Ring (adds long rod) [+$115]
Wiseco Forged, 3-Ring (adds long rod) [+$135]
Select Carburator

22mm Mikuni - Gas
GX390 Carb - Gas
.650 Bored , Ru*ing (Chinese) - Gas [-$35]
SA Extreme Carb - Gas [+$20]
SA Extreme - Methanol [+$20]
GX390 Carb - Methanol [+$20]
24mm Flat Slide Mikuni - Gas [+$100]
28mm Flat Slide Mikuni - Methanol [+$120]
Tillotson 304 - Gas [+$100]
Tillotson 334 - Methanol [+$100]
Select Compression Ratio

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

No Crankshaft
OEM Genuine Honda [+$80]
OEM Honda, Balanced [+$180]
.060 Stroker, Honda Core, Balanced [+$280]
.175 Billet Stroker (includes Wiseco Piston) [+$375]
Valve Size

25mm Intake, 24mm Exhaust, Stainless
27mm Intake, 24mm Exhaust, Stainless
27mm Intake, 25mm Exhaust, Stainless [+$20]
28mm Intake, 25mm Exhaust, Stainless [+$59]
32mm Intake, 28mm Exhaust, Stainless [+$119]
Select Valve Springs/Retainers

Aluminum Retainers
Titanium Retainers [+$10]
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)
Isky Black Mamba [-$30]
307 0807 (Drag Race Only)
Select Flywheel

No Flywheel
Dyno PVL Cast Aluminum Flywheel (w/4 degree key) [+$50]
ARC Billet Flywheel (Use stock Key) [+$85]
Small Diameter Flywheel, Adjustable [+$180] THE BEST!!
Super Light, ARC 6602 & Small Fan (use stock key) [+$95]
Lightweight Billet Aluminum w/PVL Digital Ignition System [+$229]
Additional Options

Add Roller Rockers (spacer included) [+$110]

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

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