​To place a order call (530)533-6069 or email us at s1sound1@yahoo.com. Free shipping over $250.00 excludes fenders, wheels/tire , and engines ship for $40.00 

There are no installation instructions, but if you can replace a piston, you can install these kits. 
If you don't have any experience working on your engine, we highly recommend having a professional technician install these kit. The parts are installed in the same manner as OEM parts.

146cc Big Bore Cylinder Kit

  • Lightweight aluminum cylinder with steel sleeve 57mm high compression piston w/13mm wrist pin. For engines with big valve cylinder heads(27/23mm or 30/23mm) and 57mm stroke.
  • No case machining needed


  • Installation notes: Its very important that you use Honda bond (or similar quality) sealer on the head gasket.  Also, don't use the original o-rings between the head and cylinder (not needed) but do re-use the large o-ring at the bottom of the cylinder between the cylinder and the engine case at the oil return.

57mm Replacement Piston Kit

  • Includes Piston, Rings, Wrist pin and Gasket set


12 Volt High Volume Oil Pump

  • Recommended with the big bore kit.
  • Must drill oil outlet on case to 2mm or 5/64".

Clutch case Gasket sold separately

KLX style V2 Race Head

  • Roller rockers, 30mm Intake, 24.5mm Exhaust valves, Race Camshaft, Head Gasket Kit
  • KLX Style Intake and Exhaust Ports
  • Use with 170-184cc Big Bore Kit.


​90cc-160cc Engine Performace

TRX90 114cc Complete Kit

  • Includes:
  • 20mm OEM Carb w/Jet Kit(works with stock ATC70 throttle and able. Use stock TRX90 manifold.)
  • 54mm Aluminum cylinder w/54mm High compression Piston
  • New Race head with larger 25/22mm valves and high performance camshaft w/Honda cam sprocket
  • Head gasket kit
  • Uni air filter
  • Throttle Cable(if needed)
  • No case machining needed 


China 86cc -107cc ("90cc-110cc") 114cc Complete Kit 

  • Engine must have 49.5mm stroke and 13mm wrist pin.
  • Does not work on motors with 3 valve head.
  • Same as kit above but includes:
  • Intake manifold, Oil Side Cam Cover, Cam Sprocket/Pin
  • Note: 
  • On bottom mount electric start motors, some of the cooling fins on the bottom 
  • side of the cylinder will have to be ground down to clear the starter.

114cc Cylinder Kit

  •  No case machining needed 


KLX Big Bore Kit

  • All aluminum ceramic plated 64mm cylinder
  • New high compression piston with extended skirt for added reliability. Head gasket set included.
  • No case machining required
  • 150cc E-Start engine will increase to 170cc
  • 155cc engine will increase to 177cc
  • 160cc engine will increase to 184cc


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