MXA TEAM TESTED: R&D RACING POWER BOWL 2

WHAT IS IT? The R&D Racing Power Bowl 2 is a complete replacement float bowl and accelerator pump (with an adjustable leak jet) that refines the fuel flow on Keihin FCR carburetors.

WHAT’S IT COST? $249.95 (fits all Keihin FCR carbs).

CONTACT? www.r1dean.com or (562) 864-8218.

WHAT STANDS OUT? Here’s a list of things that stand out with the R&D Power Bowl 2.

(1) The carb drought. As the motocross world sits today, there are only two full-size motocross bikes on the showroom floors that come with Keihin FCR carbs: the Yamaha YZ250F and the KTM 450SXF.

(2) The fix. The MXA wrecking crew loves a carburetor’s organic feel, ability to produce excess fuel in advance of load situations, and the fact that it can be troubleshot without a degree in electrical engineering. In our opinion, if Keihin had hired R&D’s Dean Dickenson five years ago, fuel injection would never have gotten a foothold in motocross. Dickenson’s carburetor know-how verges on genius, as evidenced by his amazingly effective Power Bowl. The Power Bowl 2 doesn’t just address four-stroke jetting issues, but it makes the Keihin FCR as easy to tune as a television set.

(3) Float bowl. The stock Keihin float bowl works by siphoning fuel from the bottom of the cavity as the bike bounces, jumps and careens around the track. It is not uncommon for the fuel in the stock float bowl to cavitate and froth over jumps and whoops. While Keihin never gave this problem more than lip service, R&D attacked it head-on and eliminated it. The Power Bowl 2’s main jet chamber is totally sealed to keep fuel around the pickup point from sloshing away from the mainjet. To make power you need a constant supply of fuel, and the Power Bowl 2 provides it.

(4) Accelerator pump. Unlike the stock Keihin accelerator pump, the Power Bowl 2 has two separate fuel ports in the accelerator pump chamber. The first orifice is isolated at the highest point of the accelerator pump to vent trapped air out through the leak jet. The second orifice is located low in the fuel sump to insure a supply of air-free fuel to the accelerator pump circuit. This dual circuit keeps trapped air from being sucked into the pump circuit. Now, the accelerator pump can fill completely and not suck air at inopportune moments.

(5) Leak jet. One jet that most four-stroke owners never touch (and don’t know exists) is the leak jet. This unappreciated tuning tool is incredibly important, but on a Keihin FCR it is unbelievably hard to get to. It can only be adjusted by pulling the carb apart and replacing a tiny brass jet. On the Power Bowl 2, the leak jet can be adjusted by a thumb screw that aims directly out the side of the accelerator pump. This makes it as easy to adjust as the ubiquitous fuel screw.

(6) Performance. We loved it. Every MXA test rider raved about the increase in throttle response and crisper jetting. The combined effects of no frothing, better accelerator pump fuel density and instant adjustability made noticeable improvements to low-to-mid power. Bikes that had a tendency to shoot ducks at speed, pop on deceleration or bog under hard acceleration became docile after a few deft adjustments of the Power Bowl 2’s adjuster screws.

WHAT’S THE SQUAWK? No complaints.

If you own a bike with a Keihin FCR carb, you should own an R&D Power Bowl 2.