Engine balancing

A single cylinder engine can only be balanced in the vertical plane (in line with the piston travel) unless it has a countershaft balancer to affect the imbalance at 90* to the vertical.
It's kinda like SunDog said "Who pretends to do it."
 
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Single cyl go through vibration periods through the rpm range. Maybe try a different gear. You might be able to get above or below the vibration rpm.
 
How much vibration are we talking about, are you breaking things, are you cracking exhaust pipes, are you used to small engines on unsuspended vehicles? What are you comparing the vibration level too?
 
Get two knife edges . Decide on a balance factor . Bolt that weight on the crank journal . Add or remove weight on counter weight till it doesn't rotate from any position.
 
Often times this can be caused by piston wear/excessive piston to cylinder wall clearance. Get that piston chattering while moving up and down and it will vibrate the hell out of things.

Dan
 
motors arent balanced, right? i thought abt using pin type urethane shock bushings tween motor and plate. the bushings are cheap enough, but would take... one on top with washer over it, one between motor and motor plate and another under motor plate (with washers here and there) and then...??? drill out the motor mount bolt holes to 3/8" and use 3/8" bolts and blue thread lock. get bolts tight, but not so tight it splits the shock bushings?
 
The thing not being said, is that one cylinder, four cycle engine balancing is only good for a small rpm range.
After discovering the range needed to give best power, the change would net results not worthy of the effort to obtain.

The effect of the power pulse every other revolution adds a vibration of it's own.
 
motors arent balanced, right? i thought abt using pin type urethane shock bushings tween motor and plate. the bushings are cheap enough, but would take... one on top with washer over it, one between motor and motor plate and another under motor plate (with washers here and there) and then...??? drill out the motor mount bolt holes to 3/8" and use 3/8" bolts and blue thread lock. get bolts tight, but not so tight it splits the shock bushings?
Now some of the power produced by the engine is being absorbed by urethane bushings, instead of being transferred to the tires to be converted to forward motion.

The tires themselves absorb some of the energy the engine produces. Why add another power robber?
 
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