Crank balancing point?

[geir54]

I've just reasembeled my crank case halfs with a new hot rod kit on the crank shaft and it is doing somthing that seems strange to me. If I turn the crank so the rod is halfway between tdc and bdc, it rotates back to tdc by itself. It seems like there is weight or somthing on the crank directly opposite the big end bearing that is pulling it down. Is this normal? Everything went together very easily and I don't want to keep going if I have to tear it apart again. The bike is a 92 cr250. Thanks.

Do you think maybe I didnt tourque the crankcase bolt evenly enough?

 

[jmics19067]

If the crank spins freely and is always trying to keep the connecting rod end up that is normal. The crank is balanced <to a degree> with the wieght of the piston and rings assembled on it.