Quote Originally Posted by jrevens View Post
Sorry to hear of your mishap Larry, but glad the Luga is working out. Hal is definitely a good man! I guess the balance ring doesn’t have enough mass to be detrimental to the engine/gearbox? Just thinking of the angular momentum and Rotax’s limit. What does it weigh? It’s probably not an issue... just curious. As an aside, I haven’t been real impressed with some other possibly similar units used with Lycomings, based on what I would see when checking the balance. There was frequently (like at every engine start) a period of more imbalance until things settled down. I figured that the total wear & tear on an engine over an extended period of time might be greater with the ring than without (with a good dynamic balance job). It’s like comparing apples to oranges though when we’re talking about Lycoming vs Rotax. Your experience sounds really good.

The weight of of the balance ring is less than a pound, in my estimate. I didn’t weigh it directly. As far as the MMOI is concerned, I believe the impact to be negligible at most.

I do not believe the few rotations of imbalance will effect wear in the long term. On my engine, at this time with the relatively few number of startups, I can not even notice this startup imbalance. By the time the engines ignition transitions from start to run mode the balancer ring has come into its effectiveness.