1999 mercury 4 stroke with carb problems

[Chewybmt]

Hello all and thanks in advance to the input I receive!!

i have a 1999 mercury 4 stroke with 3 carbs and they are kicking my butt.
I removed the breather and can see gas shooting out of the tall stem in the carb when I rev up the engine, but as soon as I let off the gas the gas will quit coming out even if it’s full throttle and the motor bogs down and eventually dies. If I keep messing with the throttle, I can see gas goin in and it continues to run. Not much I haven’t checked on this dude. New gas can, new lines all the way to the carbs too. Disconnected the line at fuel pump and it shoots out of it fine while running. It starts and idles fine. Plugs are clean and compression is 110 on all 3.

If someone can just give me a clue what to check next I’ll be more than happy to try it.

I’ve tried just about everything I read about, need new ideas.

Thanks in advance
Brandon

 

[BillP]

My 97 50 4stk had plain steel in the carb needle /seat. You may be experiencing that. Ethanol caused rapid water corrosion and needles sticking in the seats...flooding the carbs. Been there and done it. They get stuck hard and you have to pull the carbs to fix it.

 

[Chewybmt]

I’ve pulled and cleaned carbs like 4 or 5 times and synced every time afterwards. I cleaned the seats real good and checked them out, but have not changed them out.

 

[BillP]

In that case I'd check float level or binding needle clips.