Starter Fit Problem

[Roger W Gerow]

Ok, here is my problem. Purchased a '39/'40 engine the other day without a starter attached. Had one in my inventory. The starter drive gear is too large to engage with the flywheel. By the way this isn't my first flathead experience. Had another starter which was installed. Same results. Total confusion. Everything is original. Any idea's? Thanks in advance for a solution!