Re: 1961 Elgin 40 hp
Very high RPM at full throttle in neutral???? Well I should hope so. It should have so much RPM that it likely would fly apart. That is EXTREMELY bad practice. Don't do it.
There is something wrong with that motor. Unfortunately, I can't tell what it is from here. My first suspicion would be that it is running on one cylinder, but you say you fixed that. Your suspicion that the throttle is goofed up has merit. Like I said, if it actually were running at full throttle with no load, it would maybe explode, or at least go into runaway condition.
I suggest you run it in gear, at a moderate throttle on the boat, in the lake, and disable one cylinder (spark plug or coil if they are external) at a time. Is the RPM drop about equal? If not, you will have to find out what is wrong with the weak one. But if RPM drop is about equal, give the throttle stuff a critical examination.
OK, here is a suggestion you rarely hear any more. Is the problem with the boat and not the motor? You would be surprised at how many boats I've seen with 50 gallons of water trapped under the floor. That's about 400 pounds you are lugging around. Marine growth on the bottom is another often ignored thing.
