OMC 5.0L idle issues

NavyJetMech

Cadet
Joined
Jul 15, 2015
Messages
6
Read through numerous posts before typing out my specific situation, I have some things in mind but will explain what is happening first.

89 Bayliner Capri 195
5.0L OMC Cobra HO

Ran the boat up in the driveway a couple times with no issues, seemed to idle fine right around 600RPM. Took the wife out this past Monday on our maiden voyage, started it up in the water and it idled for about 10 seconds then died, kicked it back over turned towards open water and eased the throttle...and it died. Started again, eased the throttle, it sputtered a second then we were cruising. I figured it was just cold so ran it around the lake for a 10 minutes at half throttle and WOT and then brought it back to a normal cruising speed because the wife was freaking out a bit about how fast we were going so I stopped for a bit, did some fishing while she sunbathed, caught a pike then decided to move on to another spot. Went to start the boat..tada!...nothing, crank, crank, nope. Waited a bit and finally got it turned over and same thing happened, idle..die, start, idle, sputter...whoosh off we go. I pretty much have to get it started then hit the throttle to get moving. Happened all day, which for the first time ever boating in choppy water and trying to dock with a motor that wont idle and a family of five fishing and watching me fail at docking was a bit stressful, but got her out of the water safely.

Fast forward to last night 23JUL15, ran it up in the driveway and wouldn't you know, it wouldn't idle in the driveway either, could get it kicked over then shortly after it would sputter and die, almost like it is being starved of fuel, so I adjusted the curb idle screw to bring the RPM up since it was hovering around 450 in the driveway. Got the motor to idle and put her to bed to get ready for fishing today.

Today. Welp, same thing, idle....die..well you get it. Also noticed that it seemed to be laboring a bit at WOT today on the water and couldn't reach top speed (calm water). So my plan of action is fuel filter, spark plugs, distributor cap to start but looking for insight from the community and what else I should/should not be doing. If you are reading this sentence then thanks for sticking it out with me and reading to the end.
 

MRS

Commander
Joined
Jul 10, 2005
Messages
2,580
Just went thru the same thing 86 4.3. If you have a mechanical fuel pump I would first check that, pull the line that runs from the pump to the carb. pull at the fuel pump if any gas at all comes out the diaphragm is bad in the pump. Or you can try firing up the boat and watch the carb where the hose hooks up at the top of the carb you will see gas coming out of it fuel pump is done. I am talking about the clear line that is hooked to the bottom of the pump Hope that helps.
 

NavyJetMech

Cadet
Joined
Jul 15, 2015
Messages
6
Didn't even think of the fuel pump, and naturally it is now an obsolete part, I am sure there is a cross reference but google is failing me as of right now.
 

MRS

Commander
Joined
Jul 10, 2005
Messages
2,580
I got mine from Napa also on ebay there are a lot on there.
 
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