The UFO by Thunder Products is a simple, trouble free, aerodynamic piece that fits VM Mikuni carburetors. The UFO makes a normal round slide carburetor out-perform the more expensive flat slide carburetor by eliminating turbulence and increasing air flow and velocity, creating a highly atomized fuel charge. Normal gains are 3/4 to 1 HP per 100 cc of engine displacement on 4 stroke engines and 1 1/2 to 2 HP per 100cc of engine displacement on 2 stroke engines. (Re-jetting and tuning may be required).
More horsepower with less fuel
Broader power band
Explosive throttle response
Superior fuel atomization
Less sensitive to temperature, altitude and jetting changes
Cleaner emissions
Cooler running engine
Easier starting and warm-ups
Reduces cold pipe syndrome
Works with stock or modified engines
Without the U.F.O., the air hits the forward wall of the slide cavity creating a rolling air turbulence which forces the poorly atomized fuel droplets to the lower portion of the carb bore resulting in poor fuel atomization and poor performance.
With the aerodynamic U.F.O. filling the slide cavity, the rolling air turbulence is eliminated. The higher velocity air flow pulls the fuel further up the needle and higher in the carburetor bore resulting in superior fuel atomization. This means more HP, quicker throttle response, improved fuel economy and a cooler running engine.
NOTE: When installing UFOs, the pilot jet must be reduced substantially (usually about 50%, sometimes even more).