Update: 1985 mercury 50hp runs but surges at WOT

[kschauss]

Please bear with me me as this is my first post. I have a 50hp 2 stroke that is surging or acting like it is fuel starved at WOT. If I squeeze the primer bulb it will run with out an issue for about a minute. It will also run in netrual at full rmp. I havereplaced the plugs rebuilt carbs, checked compression 120 across a four, replaced fuel line, tank, and cleaned internal lines. The I have also checked timing and idol mix as well as check spark.

I am stumped but am also to stuborn to bring it to the shop and with a new baby in the house can scarcly affordable it and my wife is running out of patientance.

Any help would be greatly appreciated

UPDATE:
I was going through the manual and started checking the electrical side and got a high reading on the strator blue and blue wht wires could this be the cause of the surging at WOT?

 

[Barnacle_Bill]

Re: 1985 mercury 50hp runs but surges at WOT

Re: 1985 mercury 50hp runs but surges at WOT

Never run your motor at WOT in neutral. Double check all your fuel lines, primer bulb and connections for cracks. If all that is good rebuild your fuel pump.

 

[kschauss]

Re: 1985 mercury 50hp runs but surges at WOT

Re: 1985 mercury 50hp runs but surges at WOT

the pumps are integrated into the carbs and use a diaphragm I have replaced a rebuilt the intended twice. R
The internal lines are solid and the line to the engine is new as is the primer bulb

 

[MassillonBuckeye]

Re: 1985 mercury 50hp runs but surges at WOT

Re: 1985 mercury 50hp runs but surges at WOT

Your Venturi intact? Ehh, nevermind. Your carb doesnt have one.

 

[kschauss]

Please see update with stator

 

[gravitysgone]

Re: Update: 1985 mercury 50hp runs but surges at WOT

Please see update with stator

I had the same problem, complete with new baby and frustrated wife. I took the carbs back off and reset the floats lower and that seems to have fixed it. my manual did not cover my exact carb, so the first time was a guess. I set the float as low as it would go and not leak out the overflow. I got a good tip on here to hook your carb right up to the tank line and pump it up to make sure it doesn't leak before installing it. I don't really know what I'm doing so take that with a grain of salt.