2011 Yamaha YZ85
Take the mighty 2011 Yamaha YZ450F, a bike which just may be the most advanced, capable, and talented four stroke large displacement motocrosser in this part of the galaxy and wash it in hot water. Really hot water. Until it shrinks. Pull it out of the tub and there you have it: The 2011 Yamaha YZ85.
Keep in mind that in the laundry cycle, two of the strokes got washed away from the engine so the motor is now a two stroke. Yes, a two stroke. If you thought that this engine technology had been relegated to the scrap heap of motorcycling history you were wrong. To paraphrase the famous words of Mark Twain, the reports of the death of the two stroke engine have been greatly exaggerated. Indeed there is some exciting new technology on the horizon which may cure the two stroke's nasty habit to guzzle fuel and spew out toxic emissions. That could lead to a two stroke renaissance in the very near future.
The YZ85 is powered by a tiny, liquid-cooled, 84.7cc crankcase reed-valve-inducted two stroke single cylinder engine fed by a 28mm Keihin flat-slide carburetor and mated to a six-speed transmission that is both remarkably light and almost unbelievably compact. This YZ85 engine is set in an extremely rigid, semi-double-cradle frame with a single backbone. The YZ85 is also blessed with fully adjustable suspension, front and rear disc brakes, and 11.1 inches of rear wheel travel which is extremely impressive when you consider that this pint sized motocrosser has a wheelbase which doesn't even stretch out to 50 inches.
Just like the big boys both front and rear suspension systems allow for 20 clicks of rebound and compression damping adjustment. There is no excuse on race day that you're not competitive because you're riding a glorified pit bike or monkey bike. The YZ85 is a serious motocrosser that just happens to be shrunk down to size to fit younger racers. As the younger racers grow up a bit, there is a special YZ85 large wheel kit available through Yamaha which converts the front wheel from to 17 to 19 inches and the rear from to 14 to 17 inches. This modification is a very welcome one as it assures that the YZ85 can keep pace with the young racer as they grow, and doesn't have to be just sold at half price on ebay.
With its jaunty expansion chamber sweeping out onto the right hand side of the cylinder, the 2011 Yamaha YZ85 reflects the noble two stroke heritage of the great Yamaha world champion motocrossers of the past. It's a wonderful choice for any young dirt racer.
2011 Yamaha YZ85 At A Glance
Base MSRP: $4,799
Engine Displacement: 85 cc
Engine Type: 2-stroke, liquid-cooled,crankcase reed-valve,single
Bore & Stroke: 47.5 x 47.8mm
Ignition Type: CDI / Kick
Compression Ratio: 8.2:1
Transmission Type: 6-speed
Final Drive Type: Chain
Front Tire: 70/100-17
Rear Tire: 90/100-14
Wheelbase: 1,255mm (49.4")
Saddle Height: 864mm (34")
Curb Dry Weight: 71kg (156.2 lb)
Fuel Capacity (US): 5 litres
* Specs/pix apply to 2010 model, updates as released