Dr. D Yz Wet Sump Conversion Kit
Dr. D YZ Wet Sump Conversion Kit
CW EVALUATION
Great idea, less weight
EACH YEAR, MOTORCYCLE MANUFACturers go to great lengths to cut not just pounds, but mere ounces, from their motocross bikes, which are already among the lightest two-wheelers going. That’s why the Dr. D YZ Wet Sump Conversion Kit, which lops a whopping 3 pounds off a Yamaha YZ250F or YZ426F, is such a big deal.
Dr. D, or Doug Dubach as he’s called in the real world, knows his way around YZs. After all, he’s Yamaha’s main development rider, as well as a former 250cc Supercross winner and multi-time World Four-Stroke and Vet Motocross Champion.
Dubach’s kit is a simple design, and mimics the setup used on the factory racebikes, which have been wetsumpers since the YZ400F days. Parts are few: aluminum plugs to cap the dipstick, frame drain and oil-return lines; a block-off plate that allows the oil pump to pick up from the engine instead of the frame; and an oil-level sight window to replace the neutral switch.
Directions are straightforward and neatly illustrated. Installation took about an hour, with most of the time spent removing the clutch basket to plug an oil passage. Changeover complete, we ended up with a handful of hardware, a pile of oil lines and half the stock oil capacity, from 1.8 to 0.9 quarts on our 2002 YZ426F. So, where’s the oil fill? Behind the screwed-inplace timing view cover.
Downside to the diet is the need for more frequent oil changes-Dubach
recommends fresh lubricant after every second race (Dr. D also sells a $37 Hour Meter to eliminate any confusion). That said, draining and refilling the cases is simple, and can be done in conjunction with routine airfilter service. For at-a-glance oil-level checks, simply sight through the aforementioned window.
Okay, so four of our five test riders were unable to detect a difference while riding the “wet” bike. In fact, only an experienced evaluator could sense an improvement in agility, mostly when in the air or throwing the bike into a turn. Still, there’s no easier or less-expensive way to slice 3 pounds off your four-stroke YZ. Plus, you’ll be one step closer to “factory.”
DETAILS Dubach Racing Development, Inc. 1420 Ritchey St. # D Santa Ana, CA 92705 714/953-7561 www.dubachracing.com Price $150 A Low-cost weight toss A Easy installation owns V Not as cool as carbon-fiber or titanium add-ons V Increased oil bills
