2000 4.3L Mercruiser turns over but doesn't start.

[Adarduk]

Trying to start my Mercruiser 4.3L and it just turns and turns but no start. I've replaced all the spark plugs. I checked the main fuel filter/water separator and its clean.

My fuel pump works. It turns on a couple seconds after cranking and I tried pluging it in directly to the battery. It turns on and runs strong in both cases. I can feel fuel flowing in the lines between the tank and fuel filter and the fuel filter to the carburetor.

I took the spark arrested of the carb but there seems to be no fuel in the bowl. I would imagine this thing should have a least a few Ozs in it but almost nothing. I can faintly smell fuel. I had someone pump the throttle and I don't see gas coming into the carb. I'm not sure if I should see gas coming in or not. This is my first time working on a I/O.

I want to try starting fluid, but I'm getting mixed opinions. Some people swear by it and others call it head removal in a can. I don't know if I should try it or not.

Main questions:

Should I see gas in the carb bowl and should there be gas coming in when throttle is pumped?

Should I try starting fluid?

Anything else that could be causing a no start?

 

[alldodge]

Should I see gas in the carb bowl and should there be gas coming in when throttle is pumped?

Yes for both. The issue is your pump is either bad and not pumping, or there is a restriction somewhere. Could be the tank pickup tube, the antisiphon valve attached to the top of the tank, hose or other fittings up to and including the filter.

Not knowing your serial number, it may also have a clogged filter/screen at the carb or a stuck float.

Should I try starting fluid?

No, its has no fuel, so using starting fluid doesn't solve anything. Only use it if you have fuel and spark and it won't run, and only small amount

 

[Adarduk]

I think the pump is good. I can feel fuel rushing into the carburetor at the fuel inlet. I'm going to try and take off the the metal pipe at the inlet of the carburetor and check for a blockage.

If like you said fuel should enter the carb when the throttle is pumped, then there has to be something preventing that.