OMC Not running!

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: OMC Not running!

Maybe it jumped time, or dist. moved during loading.
 
Joined
Apr 16, 2007
Messages
21
Re: OMC Not running!

Ok I just got done looking at the boat, I decided that doing what haut said was over my head for not doing it with someone else with more knowlege than me. So I checked some other things with the fuel entering the carb. And here is what I found......when I"m just cranking the engine trying to start it no gas is going to the carb, when I prime the engine and get it to start and throttle it to about 1/4 throttle still no gas, I only get gas coming into the carb when I have 1/2 to 3/4 of throttle and then its only a very very small trickle of gas.....What do you think???
 

Haut Medoc

Supreme Mariner
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Jun 29, 2004
Messages
10,645
Re: OMC Not running!


If it has water in the cylinders & has sat like that for two weeks it's probably too late to save it anyway....
You could check under the dist cap for signs of moisture....
Or check/change the water sparating fuel filter.....
That looks like an oil filter....
You could have some water in your gas......:)
 

Haut Medoc

Supreme Mariner
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Jun 29, 2004
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Re: OMC Not running!


The carbs purpose is to turn liquid into vapor......;)
It should not appear as a constant stream of liquid.....;)
 

Haut Medoc

Supreme Mariner
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Jun 29, 2004
Messages
10,645
Re: OMC Not running!


No, the carb gets gas all of the time....
But is converted into vapor, that you can not easily see....
The increased volume of 3/4 throttle enables you to see it....;)
I really do not think your problem is a lack of fuel.....:)
 

Gary H NC

Fleet Admiral
Joined
Dec 1, 2005
Messages
8,972
Re: OMC Not running!

Or better yet,take it to your local Marine mechanic. I know you are wanting to learn but it sounds like the DIY is not your thing.
At least buy the correct factory manual and read it over..
 

RCSConstruction

Chief Petty Officer
Joined
Mar 23, 2007
Messages
549
Re: OMC Not running!

So the carb only gets gas when in it when its over 3/4 throttle?
I believe that is when the accelerator pump kicks in (squirts).
Haut has you on the right track. After hearing about the smoke I believe you have a cracked head or head gasket.:(
Good luck, I hope it gets worked out.
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
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Re: OMC Not running!

The accelerator pump kicks in when you start moving the throttle from idle. After 3/4 throttle very little movement will occure.
The reason for the accelerator pump is to give some excess fuel on throttle up from idle where there is no vacuum to pull the fuel in.
 

Don S

Honorary Moderator Emeritus
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Re: OMC Not running!

Bruce, remember the old nylon coated timing gears that used to shed their teeth........... Not something I have seen in a marine engine.
 

bruceb58

Supreme Mariner
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Mar 5, 2006
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30,581
Re: OMC Not running!

Bruce, remember the old nylon coated timing gears that used to shed their teeth........... Not something I have seen in a marine engine.

Maybe from operating! Not from loading!
 

Don S

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Re: OMC Not running!

Loading = Grabbing at straws
 
Joined
Apr 16, 2007
Messages
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Re: OMC Not running!

Ok so I've been real busy at work since last time everone has heard from me. But this weekend I did get a chance to start the boat up again. And here is what happened......I got it started but giving it some throttle like I said before and it was running rough like before but this time I just let it run like that for awhile and I would gradually let the throttle down more and more until it was back in the idle position and after it doing this for a few min. it wasn't running rough anymore it was running fine and even idling fine, also I could start it back up with out giving it any throttle and it was still running fine. So the next day I went to start it back up and I was back at square one with it being hard to start and running rough, it takes prolly 15min. or so for me to get it to start running normal....what do you guys think? Thanks for all the help!!
 

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: OMC Not running!

I meant, the next time he started it, it jumped. When engines jump time/shear gears is usually at start-up. It now sounds like a fuel delivery problem?
 

bruceb58

Supreme Mariner
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Mar 5, 2006
Messages
30,581
Re: OMC Not running!

What is the condition of you spark plug wires, cap, points and rotor? Have they been changed recently?

Have you checked your dwell and timing?

How are the fuel filters...changed them recently?
 

#1CATDADDY

Cadet
Joined
Apr 23, 2007
Messages
23
Re: OMC Not running!

Let me know too...I have a 1991 OMC 5.7L and now I think the ESA shift interuptor is causing hard time starting and rough when it is low idle, dies , but once you get it to WOT it runs good.I don't know enough this set up and how it works let alone replace evrything. Might be your problem too though.
 
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