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Old 10-26-2010, 09:54 PM   #34 (permalink)
rmay635703
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Quote:
Originally Posted by Frank Lee View Post
The straight twins I'm familiar with incl. CB450 have pistons going up n down in unison whilst firing non simultaneously. This is how you get even firing pulses; if they fired together what would be the point? Make a big single then.
An opposing twin that is balanced makes no conter movement or vibration when both OPPOSING cylinders fire as they counteract each others momentum, a Single would make a hopping action having another single fire at the same time 180 deg opposite would cancel it out.

BMW motorcycles occasionally did this.
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