merc cruizer 350 bogging down

Hi guys
hopefully someone can help...
I have an older rear mount eliminator with a 350 merc in it... I have an issue where it works ok at 2500 ish rmp but as soon as I turn a sharp corner it boggs down and often can not re start as its flooded bad..

I took of fuel filter and it had heaps of water and garbage in it... so i replaced that and drained out both fuel tanks thinking that that is the cause. took if for a run today and id did the same and could not re start (had to get towed back :-()...

It has a manual fuel pump - should I replace with electric? I must be a fuel/carbie issue - have I got the float incorrect? I have adjusted timing etc..

Im about to take it to a mechanic however i suspect they may not be able to locate issue as the mechanic here can not run it on a lake and it runs fine..

it does also bog down some time under load on initial take of..

It has a holly carb in it but not sure of model... there is a little grub screw on each side of the float one is out heaps further then the other - is that an issue?

 

That seems to indicate that you need to rebuild the carburetor. Hollys are finicky about fuel contamination. Make sure you get the correct power-valve. There are two types and many vacuum ratings for them.

 

clogged, not bogged?

First, in most cases, electric pumps are not allowed on boats. If the engine quits or a fuel line leaks, you have a very dangerous problem.
It sounds as if you have a partial blockage in your fuel system. Just enough gas gets through to run, but not enough for higher flow. Holleys have a screen in the inlet, check it first. I would first try running from a portable outboard tank with clean (new) fuel. I do sometimes use a portable pump connected where the carb hooks up to flow test the system.
I am also assuming you have a way of checking the ignition system under load to make sure it really is a carb problem.
B