1989 2.5L Mercruiser Issues after carb rebuild

[rayodunne]

So when I launched this year I had idle and starting issues. I had no issues once I got moving. I decided to rebuild the carb, a mercarb to be precise. Now the boat starts first try and idle real smooth. I can leave the dock and throttle up but after 100 yards the engine starts loosing power and if I don't throttle back it dies. It starts right back up and I could idle all day.
When I rebuilt the carb I also changed the in pump filter. Can this be installed wrong?
One other thing I noticed when rebuilding is the long piston thing in the top cover of the carb was a little sticky. Would this be to blame?
Would setting the float height or drop wrong, cause my issues?
I used the rubber tipped spring loaded needle instead of the solid one that was in there. Would this cause the issues?
I did a lot of reading and most posts tell me to rebuild the carb but I have done that. I obviously did something wrong.
Any tips would be really helpful. Thanks.

 

[NHGuy]

I'd start by verifying or correcting your float height. It's got to be really precisely set. Correct to a 32nd or 16th of an inch. Also check the filters, seat and float bowl for debris and water.

 

[philipp10]

sounds short of gas to me. Enough to idle but once you throttle up, its not there. Check float, look for a vacuum leak, possiblyn a dirty fuel filter or weak fuel pump.

 

[rayodunne]

I'd start by verifying or correcting your float height. It's got to be really precisely set. Correct to a 32nd or 16th of an inch. Also check the filters, seat and float bowl for debris and water.

I considered taking the carb off and checking the float. Boat is located an hour from me so I will check later this week. Carb was very clean when I finished rebuild. I don't see any reason for debris or water to be in there but I will see when checking float.

sounds short of gas to me. Enough to idle but once you throttle up, its not there. Check float, look for a vacuum leak, possibly a dirty fuel filter or weak fuel pump.

Gas shortage is what it sounded like to me also. As I said above I will check the float. Where would the vacuum leak occur? These symptoms did not exist before I removed the carb and refitted it?
All filters replaced but I could have replaced the one in the pump wrong restricting flow? Weak fuel pump would be odd since I achieved WOT before rebuild.

 

[rayodunne]

One other thing I noticed when rebuilding is the long piston thing in the top cover of the carb was a little sticky. Would this be to blame?

Anyone know anything about this? From research it's the power valve piston.

 

[rayodunne]

Solved: I cleaned the power valve piston. I set the float height. I also trimmed the edge of the pump filter gasket as it had become swollen and did not sit in the pump correctly.