IAME Bendix kerfuffle

So, this starter kerfuffle has been with this old Leopard of mine for a long time. It’s been a 15 year relationship.
Top photo shows (standard Bendix), I’ll call it that because it works. It’s been altered, pinion return spring and dust covers removed.
Bottom photo shows flyweight tension spring removed from the (standard Bendix) also.

The other Bendix in the photo is stock and unaltered.
With the stock unit I get many starter/bendix kick outs. That means the Bendix engages briefly, then retracts with the starter motor just free spinning. This causes many failure to start attempts, before finally getting the engine started

The (standard) unit kicks into the ring gear, stays hooked up and starts the engine every time. But, with no return spring or tension spring. The pinion is free to come into contact with the ring gear while the engine is running, and it does.

Both Bendix units are clean and lightly spray lubed, I’m using the battery from my kart lift stand. I have video links below.

https://drive.google.com/file/d/1QHLyr1K_Q8SYiKStHhpUxgo2qnn3nIX-/view?usp=sharing, https://drive.google.com/file/d/1mieK8NXbMHqM6BA7w3zlOffypkCLsB-y/view?usp=sharing