Flywheel interchange

[Kenneth Brown]

Good evening- I purchased a srarter for ole Big John and am having a little trouble. My motor is a 1961 18 hp Johnson model FD-12. The donor motor is a 77 model Johnson 30hp. The boat man said all would work fine. We all know how that story goes right.... The starter and brackets bolted on almost perfectly, just a little adjustment. The problem lies in the ring gear. My ring gear sits high on the flywheel, the donor sat kinda low. The bendix will engage but only about 1/16 on an inch, not enough to trust. Should the flywheel off of the 30 hp fit my motor? Physiclly it looks the same otherwise but what about balance? Will this work ok?