We have developed a list of jetting specifications that we believe will help your bike run its very best. Please remember that sometimes the stock OEM jetting will work just fine, other times you may have to make an adjustment, so use our suggestions below as a guide to help with your jetting problem.

For two-stroke bikes, our jetting specs are for VP Racing C12 Racing Fuel at 0-1500 ft altitude, 70-85°F temperature, 32:1 pre-mix oil ratio. We recommend Maxima Castor 927 High Performance 2-Cycle Oil.

For four-stroke bikes, our jetting specs are for premium pump gas at 0-1500 ft altitude at 70-85°F temperature.

Please Note: The stock OEM jetting for your specific model is listed first, followed by our recommended jetting underneath that model.

1989

ModelMainPilotNeedlePosScrewPowerSlideNozzleLeakOther
Honda

CR80R



















Pro Circuit12852STD2nd1.5









CR125R



















Pro Circuit16862STD2nd1









CR250R



















Pro Circuit172STDSTD3rd1.5









CR500R



















Pro Circuit17252STD3rd1.5









Kawasaki

KX60



















Pro Circuit20030STD2nd1.5









KX80



















Pro Circuit14058STD2nd1









KX125



















Pro Circuit15558STD3rd1.5









KX250



















Pro Circuit17255STD2nd1.5









KX500



















Pro Circuit17060STD3rd1.5









Yamaha

YZ125



















Pro Circuit29022.5STD2nd1.25









Suzuki

RM125



















Pro Circuit36060STD2nd1









1988

ModelMainPilotNeedlePosScrewPowerSlideNozzleLeakOther
Honda

CR125R



















Pro Circuit1656014693rd1.5









CR250R



















Pro Circuit1756213472nd1.5









CR500R



















Pro Circuit1685813702nd1.75









Kawasaki

KX125



















Pro Circuit1726813683rd1.5









Suzuki

RM250



















Pro Circuit1706813683rd1.5









1987

ModelMainPilotNeedlePosScrewPowerSlideNozzleLeakOther
Honda

CR125R



















Pro Circuit1656214683rd1









CR250R



















Pro Circuit1706013682nd1.75









CR500R



















Pro Circuit1685813702nd1.75









Suzuki

RM250



















Pro Circuit1706813683rd1.5









1986

ModelMainPilotNeedlePosScrewPowerSlideNozzleLeakOther
Honda

CR125R



















Pro Circuit1586514703rd1









CR250R



















Pro Circuit1706013683rd1.75









CR500R



















Pro Circuit1686013723rd1.75









1985

ModelMainPilotNeedlePosScrewPowerSlideNozzleLeakOther
Honda

CR125R



















Pro Circuit1526214723rd1









CR250R



















Pro Circuit1586513683rd1.5









CR500R



















Pro Circuit1686513703rd1.75










1984

ModelMainPilotNeedlePosScrewPowerSlideNozzleLeakOther
Honda

CR500R



















Pro Circuit162683143rd1.5









ATV

ModelYearMain2nd MainPilotNeedlePosScrew
Honda

TRX250EX2001122

38StockN/AN/A
Pro Circuit2001N/A









TRX300EX1993-2007122

38StockN/AN/A
Pro Circuit1993-2001N/A

N/AN/AN/AN/A
TRX400EX

148

38Stock



Pro Circuit

158

58Stock

Stock
Yamaha

200 Blaster1988-2002230

32.5Stock



Pro Circuit1988-2002240

32.5Stock

Stock
350 Banshee1987-2002200

25Stock

Stock
Pro Circuit1987-2002260

25Stock

Stock
Mod Motor1987-2002Dyno Jet Kit









Raptor 660200114014522.5Stock

1.5
Pro Circuit200114515022.5Stock

2
Grizzly 650













Pro Circuit













Suzuki

LTZ400

N/A









Pro Circuit

160









Kawasaki

KFX400

N/A









Pro Circuit

160