Motor vibration roadstar
Vibration, like engine noise, is a very subjective observation or condition and does not translate well in written text. It is something that has to be heard and experienced to be able to truly make an accurate and meaningful assessment.
That having been said, I will attempt to respond to your inquiry, based on my experiences with the Road Star.
First of all, it is a BIG V Twin engine that is not in harmonic balance at all. The very nature of the engine guarantees it is going to vibrate. Yamaha, along with about everyone else marketing a V twin, knows it and embraces it, as they market it as "character" of the motorcycle,
You have two pistons about the size of coffee cans running up and down inside your cylinders. When they go up and down, they create vibrations.
The cylinders do not fire 180 degrees apart either. They fire in a syncopated rhythm and that too generates vibration.
Yamaha has engineered the engine so that at common RPM's, such as highway speeds, the engine is smoother. This is an incredibly sophisticated piece of engineering to get the vibrations to cancel each other out, to a degree. The thing about that is, it is very much RPM dependent. It only works in a very narrow RPM range to generate the counter acting vibrations that yield the smoother, vibration canceling frequencies.
About the only thing you can do is maintain a good state of tune on your engine. Make sure the engine mounting bolts remain tight, and find the RPM's where the engine is the smoothest and try to ride it in that RPM range as much as possible.
Think about other engines, especially ones that are considered smooth. They are usually at least 4 cylinders, if not 6 or 8, because the more power pulses generated, the smoother the engine runs. Also, many are fitted with counter balancers that help cancel vibrations as well.
It is obviously not practical to add cylinders or counter balancers to your engine.
As long as you are describing vibrations that you say are common to the Road Star, it is doing what it was designed to do, and there is little if anything that can be done to alter it.
Oct 04, 2009 |
2007 Yamaha Road Star