Mercruiser 3.0 carburetor

Cest Bon

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Aug 30, 2020
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So I am new to boating. I just bought my first boat which is a 2001 Bayliner Capri Classic 1950. I got a good deal because the motor was cracked. I put a new motor in it and installed the new carburetor that came with the cracked motor. The carburetor came from National Carburetors. Anyway, everything worked great The first time out, but then when I took it out again the carburetor was not spraying fuel through the jets at all. Took the linkage loose and manually worked the throttle and still no spray. I got the boat home and took the carburetor apart. Noticed that the seal or whatever around the plunger for the throttle advance was broken. Sent the carb back to NCI and they rebuilt it and sent it back. Took it out again, and again it worked great. Better than the first time. Then I took it out again and again it died when I throttled up. Again I took the linkage apart and discovered that the carb was not spraying fuel. Took it home, took it apart, and this time everything was intact. And yet with it apart I was able to push the plunger into the cylinder and spray fuel through the jets. Put it all back together and it runs fine in the driveway. Any idea why my carb stops working? I should mention that I’ve completely drained the gas tank and put new premium fuel in it since I got the boat.
 

alldodge

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Whats the motor serial number?

First carb had an issue and was fixed
Current carb, I'm thinking you have an issue between the tank and the carb and not the carb itself

Has the fuel filter been changed?
Does the fuel pump supply a good stream of fuel when cranking?
 

Cest Bon

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Serial number is M045477. I deleted the mechanical fuel pump with an Edelbrock electric pump. Also, the pump came with a new filter.
 

alldodge

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If tank was cruddy it may have already clogged the filter
Do you see a good stream of fuel with pump running?
 

Cest Bon

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Serial number is M045477. I deleted the mechanical fuel pump with an Edelbrock electric pump. Also, the pump came with a new filter.
 

Cest Bon

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There is a good stream of fuel, but I haven’t checked the filter yet. I’ll check it tonight. When I first got the motor running I did run it with old fuel, and when I began having carb issues I noticed some junk floating around inside the carb. I emptied the fuel tank and put new premium gas in it. But you’re right, the damage may have already been done to the filter.
 

alldodge

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You have good spark so only thing is needed is gas

There is a good stream of fuel

Having a good stream of fuel then it could be a dirty carb. Now if the stream get lower as load is applied (on the water) then it could be the filter or other going back toward the tank
 
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