Re: 71' 9.5hp Johnson Help?
....would that cause cylinder to not fire? You bet it would, because there'd be little fuel to burn in that cylinder. Two stroke motors rely on having an airtight crankcase to port fuel mix into the cylinders. Another problem with the top seal leaking is , as you've already observed, oil gets sprayed everywhere under the flywheel. Oil can foul the point sets, causing misfires and holds dirt. After you replace that top seal, there's no need to replace the point sets, just remove , clean and adjust for proper point gap (.020). Clean coils , condensers and armature plate as needed. The point sets should be dry but the point cam should have a light film of machine oil applied. There is usually a small felt pad touching the points cam. The felt has a few drops of oil applied and lubes the cam as it rotates. Checking the point gap every few years, depending on usage is a part of normal checkup procedure. The vibration can be caused from dropping spark to one cylinder or a mis-adjusted carb. Did you get a chance to check the compression on each cylinder?
