what makes a motor counter balanced?

[accorracer]

just like the title says. what makes a motor counter balanced? i see alot of people talking about the cr 250 motors not being counter balanced. what is counter balancing and what causes a motor to get that way

[2004TRX450R]

When it has a counter ballancer in it. It is a weighted shaft that spins opposite the crank shaft to offset it weights. A counterballanced engine is much smoother and has less vibration than a non countercallanced engine. Most if not all dirt bikes are not counterballanced where most if not all ATVs are. I know I have heard of guys putting CR500 engines in ATV chassis and shakeing them apart and causing cracking.

[wilkin250r]

In a nutshell. The piston is moving up and down, correct? This up and down motion obviously causes vibration, and it gets worse the faster the engine is revving. The solution is to add another moving wieght that offsets the piston. This is the counterbalance, and it's right next to the crankshaft.

The counterbalance is just another piece of mass inside the engine. As the piston goes down, the counterbalance goes up. Basically, it's vibrating exactly opposite the piston, and they cancel each other out.

While the piston is moving up and down in a straight line, the counterbalance is actually moving in a circle, but then again it's also offsetting vibration other than the piston, and would require a much more lengthy explanation that neither you nor anybody else want to be bored with.

[MIKE400EX]

Wilkin, you sure come up with some good explanations for a guy that's in kindergarten! (J/K)

[seatec]

Thanx for the explanation. You see, i always thought that it only countered the rotation of the crank since it (because it fully rotates) produces more vibes than the rod and piston.

GLad to be wiser now.

[accorracer]

thanks guys you have cleared it up for me

[wilkin250r]

Originally posted by MIKE400EX
Wilkin, you sure come up with some good explanations for a guy that's in kindergarten! (J/K)

I'll be starting Kindergarten next Fall, I'm only 4 and a half now... :D