the Yamaha V-Max

The Yamaha V-Max is the original power cruiser. When launched in 1985 there was nothing quite like it. The bike was panned by enthusiast magazines for its ill-handling, but praise for its 1197cc, liquid-cooled, DOHC, 70-degree V-Four engine outshone any negativity and earned it early honors and, later, cult status.
Key the Yamaha V-Max’s legend is its bombshell engine. Sourced from Yamaha’s touring machine, the Venture Royale, engineers went to work altering cam profiles,lightening pistons and increasing the strength of connecting rods. The most important performance feature, however, was the V-Max’s “V-Boost” system.

The engine was fed via two banks of two 35 mm constant-velocity carburetors, each carburetor feeding one cylinder. Between the two banks of carburetors was a butterfly valve attached to a small motor. When the engine revved past 6,000 rpm, the butterfly valve would open and allow the fuel mixture from both banks of carburetors to flow into the one chamber feeding all four carburetors. The result, in the hands of a pro dragracer, was a power boost that accelerated the Yamaha V-Max through the quarter-mile in under 10 seconds. The combination of unique styling and straight-line performance made the Yamaha V-Max an instant classic.

In 2008 the Yamaha V-Max was noticeably missing from Yamaha’s model line-up, only to be replaced by an all new Yamaha VMAX in 2009. The Yamaha VMAX featured an aluminum frame, fully-adjustable suspension, a slipper clutch and ABS but the big news, as with the original model, was the bike’s engine.

The new Yamaha VMAX was powered by an all-new, liquid-cooled, DOHC, V-Four engine displacing 1679cc (a nearly 500cc increase). Where the old bike produced 120 horsepower the new Yamaha VMAX put out a massive 174 hp and 113 lb.-ft. of torque.

Because the new Yamaha VMAX was fuel-injected and not carbureted, Yamaha had to devise a new V-Boost system. Yamaha Chip Controlled Intake (YCC-I) and Yamaha Chip Controlled Throttle (YCC-T) were the replacements. At 6,650 rpm YCC-I shortens the length of the intake tracks from 150mm to 54mm in only 0.3 of a second. The YCC-T controls the throttle valves by computing input from a variety of sensors and calculates the best combination of EXUP setting, throttle position, ignition advance to provide controllable power.
Unlike the original Yamaha V-Max,the new version doesn’t lurch forward with a sudden surge in power, but rather utilizes modern technology to smooth and broaden the power delivery. With 174 horsepower, however, there’s no shortage of power anywhere in the VMAX’s rev range.