AQ131D starts idels and runs good then after about 30 mins bogs down

[boat nut 1243]

I have changed over to hot spark ignition changed coil rebuilt carb set timming cleaned plugs added fuel additive and fresh gas! can't find a fuel filter anywhere vent tube seems to be clear fuel came out overflow when I filled tank. if I return it to nuteral for a minuite or so it will take off again full power then after a few minutes it bogs down again! Any help would be appreciated thanks! its a 1988 19ft citation cc with 275 VP Out drive

 

[captmello]

I would add a fuel/water separating type filter between the tank and fuel pump. To me it sounds like a fuel issue. Sticky needle or float out of adjustment, clog in the fuel supply...

 

[boat nut 1243]

What do u mean sticky needle ? there is no adjustment on the float it just swings on a pin my rebuild kit didn't come with a new float and the mixture needle wscrew was the wrong one so I used the old float and old mixture needle screw! I have tried to adjust the mixture screw dosnt seem to help my problem! will install water seperater fuel filter as suggested! I'm also going to replace fuel lines comming from tank to fuel pump!

 

[captmello]

I was referring to the float needle. I guess i figured you had one, but I've never worked on one of those carbs. That rebuild kit doesn't sound very good...The mixture screw is the idle mixture. I would fix the problem first, then replace lines and add the filter. If it were me i would figure out a way to test the fuel volume at the carb by removing the fuel line, removing the coil wire and grounding it, turn the engine over and see how much fuel your getting. Do it safely by routing the fuel line into a jar or safe container. I would expect the fuel pump to pump 16 oz of fuel in 15 seconds of cranking the engine.

 

[jerryjerry05]

The pickup in the tank.
Depending on the manufacturer it could have a filter on the end.
It could be clogging.
The "new" electronic system.
When it's running? Check the coil for being overheated.
If it's too hot to keep your fingers on it then it's breaking down.
What's the voltage going to the hot side of the coil?
The voltage out of the coil?
Should probably be 9v.in and out.

 

[bergadam]

Just a thought, have you check where your choke plate is located when the engine is at operating temp? If you are running your choke to rich that could cause a bog issue.

 

[captmello]

Just a thought, have you check where your choke plate is located when the engine is at operating temp? If you are running your choke to rich that could cause a bog issue.

Those carbs have no choke.