I have 2001 Honda BF90A that has a big problem with water intrusion into the flywheel cavity. I run in salt water. So my last starter motor lasted just 2 months before loading up with corrosion and guck. This is almost certainly the failed shaft seal that was the subject of a Product Service...
I'm dusting this thread off after all these years to try to consolidate this solution, and get in a question of my own. I have 2001 Honda BF90A that has a big problem with water intrusion into the flywheel cavity. I run in salt water. So my last starter motor lasted 2-3 months before loading...