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We ran the original 750 kit with out a counter-balancer in the crank but weighted to the correct balance factor for a counter-balncerless system. The engine was smooth and didn’t seem to need a counter-balancer in this configuration. However once we had added the weight to the big-end pin, piston and conrod the whole dynamics changed and we began to see bad vibration in some chassis but none in others.

We tried all sorts of balance factors, this is often necessary anyway when you alter a single-cylinder engine and is only able to be empirically derived in most cases. After many trials and finally a cracked engine mount we decided we would have to loose some weight from the components to get it to work and re-install the counter-balbacer.

This entry was posted on Wednesday, April 30th, 2008 at 10:08 pm and is filed under Engine Develoment. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.