Product Evaluation - "Dial-A-Jet" - ATV Sport

Thunder Products

      Dial-A-Jet

     What would it mean to you engine tuners out there if we told you jetting our Yamaha Raptor for temperature and altitude now takes 15 seconds instead of 45 minutes?  Oh, and did we mention our Raptor doesn�t have any more lean spots in its powerband?

     Thunder Products has a gizmo that we are excited about.  It�s called Dial-A-Jet, and for those who like to run at peak horsepower, this product is invaluable.  Available for any ATV with a carb, the Dial-A-Jet allows jetting to be changed with a turn of a dial instead of jet wrenches.

     Explaining the principle behind Dial-A-Jet might require a degree in acoustics.  However, we can give a simple explanation for the skeptics out there.  Is is a simple fact; engines do not like to be fat (rich condition).  More horsepower is created in that fine line between running perfect and burning an engine down.

     Dial-A-Jet takes the power-producing lean condition and maintains the air-fuel mixture to the point where the engine will not detonate or burn down�and it feeds fuel based on engine demand so it never runs too rich or too lean.  This is accomplished via a tubing system that feeds a fine consistent mist of emulsified fuel instead of raw liquid fuel like all other jetting circuits in a carb.

The easy-to-install Dial-A-Jet could
 make your riding life easier.

                                                                        
     Delivered after the carb�s slide, the Dial-A-Jet�s pre-atomized fuel fills the lean spots normally found in the inefficient fuel atomization of the stock fuel circuits.  Fuel comes from the float bowl, and air comes via the air correction circuit mounted on the carb.  The Dial-A-Jet has different-sized holes (air correction circuits) with each adjustment�a bigger hole means more air will enter the mixing chamber for a leaner fuel mixture and, vice versa.

     As for the jetting part, the dial on the outside of the carb allows the user to richen or lean the amount of fuel delivery by turning the dial into one of its five positions.  We haven�t needed to adjust the Dial-A-Jet due to the high degree of automatic response the system has.

     Confused?  We were, too.  That is until we rode our Dial-A-Jet-equipped Raptor.  Compared to stock, our Raptor�s throttle response is much crisper on the bottom end�thanks to adequate fuel atomization�and the engine does not feel �flat� on top.  It is like having fuel-injection instead of a carb.

     Power gains were nice as well.  With some airbox mods and the Dial-A-Jet system, we increased power delivery by approximately two horsepower across the powerband, and noticed a significant smoothing out of the fuel curve.  We�ve seen similar results on a 400EX.

     Many riders never touch the carb�s jets�that is okay�but those riders are missing out on as much as a 15-percent horsepower gain by leaving the stock jetting untouched.  The installation was easy and straight forward.  Single carb kits are $70, and twin carb kits are $110.  Snorkel kits cost $10 each � Chaz Rice