I have a Chrysler 55hp electric Model #555HC serial #1293. It's on 1971 chrysler tri hull 15ft.. ( I think the motor is newer than the boat) with Chrysler single lever control. I started hearing a tap when shifting into 1st. As the day progressed more tapping and not going in all the time befor throatal starting to engage and rev. every now and then it will catch and pop out. With the motor off it engages fully at not quite a 3rd throatal. some tapping sound while going into revese . New to outboards,any help appreciated