FORGOTTEN MOTOCROSS TECH: THE YAMAHA OW500 PANCAKE PIPE
Motocross history is filled with examples of creative ideas that were heralded as ground-breaking, but, because of the rapid rate of change in development, sank into the swamp of forgotten technology. Although some are best left abandoned, others were truly innovative—if not ultimately successful. MXA reveals motocross’ tech trivia. Do you remember the pancake pipe?
There was a time when the aftermarket sold air scoops to cool down air-cooled two-stroke cylinders. It came and went when water-cooling came in—which brought about the most unique air-cooling idea ever devised. Yamaha’s engineers didn’t have a water-cooled works bike ready to go in the 1980s and had to make the best of what they had.So, driven by a desire to aid engine cooling, even if it cost some horsepower, they flattened the main cone of their works YZ490 (OW500) exhaust pipe.
Hakan Carlqvist: 1979 250 and 1983 500 World Champion.
By making it flatter they were able to make a clear path for air to flow to the cylinder fins. The flat pipe was a metal scoop that drew air through the cylinder fins. Called the “pancake pipe,” it was raced by 1983 500 World Champion Hakan Carlqvist.