Hi There I am working on a 74-79 evinrude 9.9 horse tiller. The owner shifted hard a few times without letting the engine revs drop. Now it seems the linkage is stuck. ( I cant force the shifter from forward to reverse)What could be the problem? AND more importantly, how do I access the linkage to inspect and repair it. Links to assembly drawings would also be most helpful. Thanks in advance for any assistance.