Help! OMC 4.3 - runs when I dump fuel directly into carb.

rsdickson

Recruit
Joined
Jul 29, 2013
Messages
2
Hi all,
First post with iboats, but definitely not my first time here! Thanks for all the help I've received already!

Just picked up a 1993 Sunbird 18' Bowrider with an OMC Cobra 4.3L in excellent cosmetic condition for very short money. The dealer that I purchased the boat from claimed to have put a new fuel pump in recently, and the fuel pump "looks new". The boat has not been run for 5 years, as it was stored for a gentleman who stopped paying for his storage bill- hence the sale.

Boat was not running, but I got the starter issue fixed and replaced the coil and got it to fire up by dumping some fuel into the carb directly. There was very little old fuel in the tank, and I put 5 gallons or so of new fuel in. Cannot keep the boat running for more than 20 seconds or so, after dumping fuel into the carb. Previous owner had installed a bulb primer in line before the fuel pump, and according to the dealer it was because he didn't want to have a new fuel pump put in. (That was before the fuel pump was allegedly replaced). Could this running problem be a carb issue from sitting for so long? Could I have a bad fuel pump relay causing the issue? Could it just be some bad gas in the system that I need to get out? Where should I begin!?
:facepalm:

Endless thanks in advance.

IMG_4314.jpg
 

Levinz11

Senior Chief Petty Officer
Joined
Apr 1, 2012
Messages
726
Re: Help! OMC 4.3 - runs when I dump fuel directly into carb.

Hi all,
First post with iboats, but definitely not my first time here! Thanks for all the help I've received already!

Just picked up a 1993 Sunbird 18' Bowrider with an OMC Cobra 4.3L in excellent cosmetic condition for very short money. The dealer that I purchased the boat from claimed to have put a new fuel pump in recently, and the fuel pump "looks new". The boat has not been run for 5 years, as it was stored for a gentleman who stopped paying for his storage bill- hence the sale.

Boat was not running, but I got the starter issue fixed and replaced the coil and got it to fire up by dumping some fuel into the carb directly. There was very little old fuel in the tank, and I put 5 gallons or so of new fuel in. Cannot keep the boat running for more than 20 seconds or so, after dumping fuel into the carb. Previous owner had installed a bulb primer in line before the fuel pump, and according to the dealer it was because he didn't want to have a new fuel pump put in. (That was before the fuel pump was allegedly replaced). Could this running problem be a carb issue from sitting for so long? Could I have a bad fuel pump relay causing the issue? Could it just be some bad gas in the system that I need to get out? Where should I begin!?
:facepalm:

Endless thanks in advance.

View attachment 205437

Since you got the boat so cheap you should probably expect to put some initial money into her. For me that would mean FULL tune up and fuel system maintenance.

You mention relays. Are you sure it has an electronic fuel pump?

Any carb sitting for years will need a rebuild.
 

rsdickson

Recruit
Joined
Jul 29, 2013
Messages
2
Re: Help! OMC 4.3 - runs when I dump fuel directly into carb.

Since you got the boat so cheap you should probably expect to put some initial money into her. For me that would mean FULL tune up and fuel system maintenance.

You mention relays. Are you sure it has an electronic fuel pump?

Any carb sitting for years will need a rebuild.


Thanks for your input! - Yesterday I replaced fuel/water separator, fuel pump relay, rebuilt carb, changed plugs, and spent 6 hours on the water!
 

Levinz11

Senior Chief Petty Officer
Joined
Apr 1, 2012
Messages
726
Re: Help! OMC 4.3 - runs when I dump fuel directly into carb.

Nice work. Have fun Dickson.
 
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