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tubarney · March 22nd, 2013, 02:57 AM

I haven't touch it from stock. The reason is when you spin it up it is closer to dead on (0) with 100% than it is with a 50% balance factor. A lot closer.

v6's and v8's use 50%. These cranks have perfect primary and secondary balance. Ninja 250 does not. This is why I'm thinking 100%. I guess I will find out the hard way.

This is the same reason as why I am not knife edging it. Because this would make it 2 far off with 100% to balance it without a sh** load of mallory

Any crankshaft that can not be folded in half and the the main journals and crank pins all line up needs bob weighs to be balanced. Inline 4 for example don't need bob weights(also why you can easily remove balance shafts). Ninja 250 needs bob weights.

What they were trying to say it that they don't have that size (journals too small) and they would need to make some up if it didn't have 3/4 inch throw.

March 22nd, 2013, 02:57 AM	#36
tubarney ninjette.org sage Name: Brad Location: Sydney Join Date: Mar 2012 Motorcycle(s): Ninja 250r 2010 SE Posts: 573	I haven't touch it from stock. The reason is when you spin it up it is closer to dead on (0) with 100% than it is with a 50% balance factor. A lot closer. v6's and v8's use 50%. These cranks have perfect primary and secondary balance. Ninja 250 does not. This is why I'm thinking 100%. I guess I will find out the hard way. This is the same reason as why I am not knife edging it. Because this would make it 2 far off with 100% to balance it without a sh** load of mallory Any crankshaft that can not be folded in half and the the main journals and crank pins all line up needs bob weighs to be balanced. Inline 4 for example don't need bob weights(also why you can easily remove balance shafts). Ninja 250 needs bob weights. What they were trying to say it that they don't have that size (journals too small) and they would need to make some up if it didn't have 3/4 inch throw.