As mentioned in a earlier post, my mm overrevs. I want to get the rpms down, but I dont want to go higher up on the gearing, steeper on the helix or softer on the secondary. I know that the primary can be tuned by adding rivets to the weights, but if that isn't enough to get the rpms down, I can go with a spring with less end force. But I don't understand, why would I want to go with a softer spring? Won't the weights just slam it easier together? Is my current primary spring too stiff for the weights? Shouldn't it be, the more power, the harder the spring?