1979 35hp evinrude boggs down around 1/4 throttle

[Seanymph35e]

I can get my boat to about a 1/4 throttle and it bogs down in the water. Out of the water it will go all the way up in gear and with just the throttle. Power pack just went bad but it did that before. I replaced the tank, spark plugs, fuel line from motor to tank. Carb was rebuilt last year. I'm thinking of changing the fuel pump assembly since it doesn't like to seal all the way sometimes and possibly rebuilding the carb again. Linkage on the timing and carb look to be working properly. Any thoughts or suggestions?

 

[racerone]

Most motors wll rev up in nuetral / on the trailer with one of 2 cylinders working.----------That test means nothing.----------Test compression.------------Test for strong spark.

 

[JoeFromAkron]

I have very little business chiming in on anything here but I have a 78 35 HP that was doing something like that. Turns out the fuel pump diaphragm was leaking gas into the crankcase causing flooding. My motor was bogging/stalling/flooding if I let it run at low speed to long and throttled up it would die. To check if the fuel pump diaphragm is bad you can take it off and see fuel/oil in the port hole.