Get Rich Quick

     There are a lot of incorrectly jetted ATVs motoring around.  We know, because we've ridden some of them.  You know the type-hard starting, dead spots in the throttle response, weak top-end power or blubbering.  It may sound strange, but quads with modifications are some of the worst running machines we've seen.  That's because jetting often needs to be richened for the improved breathing of modifications like high performance air filters and exhausts.

 

DUMB AND LAZY?

     Most riders know very little about jetting carburetors.  Some just don't want to struggle with carburetor adjustments.  We don't blame them.  ATV carbs are usually nestled into cramped areas and dealing with their tiny screws, clips and jets can test the patience of professional mechanics.  Jetting a carburetor properly means getting the air-to-fuel ratio spot-on for your machine at low midrange, and wide-open throttle.  That means you've got to adjust three systems within the carburetor that handle these speed ranges.  Even when you get it right, a big change in temperature or elevation may call for more adjustments.

 

PAIN RELIEVER

     The Dial-A-Jet is a product claimed to relieve much of the pain of jetting.  Using a siphon fuel feed from the carburetor through a precise valve that feeds atomized air and fuel through a nozzle near the mouth of the carb, it allows external air-fuel mixture adjustment.  Before you drop kick all the jets you have toward the nearest dumpster, you should know that the makers of Dial-A-Jet recommend reducing your machine's main jet two sizes if you wish to take advantage of the full range of adjustment it can provide.  Our test subject, a Honda 400EX, was already too lean because someone had removed that airbox lid, so we opted to add the device without changing the main jet to see if the Dial-A-Jet alone could correct the lean condition. 

 

NOT AFRAID OF NEEDLES

     Installing the Dial-A-Jet was simple.  A fitting replaces the drain screw at the bottom of the carb.  After you make a hole in the intake boot, you insert the Dial-A-Jet nozzle.  The valve/nozzle assembly attaches to a zip-tie, which holds it in place on the air boot.  You then run a small hose from the fitting on the carb to the Dial-A-Jet valve.  Since the Dial-A-Jet draws in air as well as fuel, a filtered snorkel kit for the device is required for ATVs.  It's an extra-cost item, but it keeps dirt out of the Dial-A-Jet and your carb. 

 

FEELING BETTER

     Even without turning the adjuster on the Dial-A-Jet, our initial test runs revealed that the Honda was running a bit better.  That makes some sense; it was getting more fuel.  It still didn't have the solid, even pull of a well-tuned stocker with it's airbox lid in place, so we cranked the adjuster to position five, full rich.  It ran too rich, so we clicked to number four.  Still not right, but better than the stumbling lean response we had before we installed the Dial-A-Jet.  We settled on position two and found ourselves with a crisp running 400EX.  The Dial-A-Jet is the easiest was to adjust jetting that we've tried.  It can't replace re-jetting entirely, but it's great for fine tuning.  It certainly beats the tedious, trial and error open-carburetor surgery we're used to.

     Rating:*****.  Price: $74.95. Snorkel Kit $10.