Reply To: Shaking at High RPM Running 1955 Evinrude Fleetwin Aquasonic 7.5HP

[Don]

Boy o boy, thought only I had this kind of luck….I’m surprised it didn’t throw a rod…I’ll bet it vibrated quite violently…
OK, so now you have a replacement powerhead but it doesn’t pump water correctly?
Seems like the powerhead has to come off again….Did it pump correctly with the old powerhead? Did you have the gearcase off again when you installed the replacement powerhead?
If the engine pumped water fine with the old powerhead, and you didn’t pull the gearcase off when you replaced the powerhead, perhaps there is an obstruction in the new powerhead…Did you do a compression test on the replacement powerhead, maybe the head gasket is blown.
If you pulled the gearcase when you replaced the powerhead, perhaps you misaligned the water tube/grommet.