OMC Not running!

[DenWbaseball1984]

"Hear is the problem.....I de-winterized my 1991 Forester with an I/O OMC
5.0L Cobra about 2 weeks ago, the
fist turn of the key it fired right up and ran great, I didn't have it on the
river just on some water. This weekend I went and tried to start it again and I
couldn't get it started, finally I got it started by giving it 3/4 of throttle
while turning the key. But then when I'd back the throttle off it would die on
me, and to top it off when I did start and was running it was running really
rough! I first thought it could be bad gas from winter so I put some new gas in
and no change...then I took off the fuel/water separator thinking that could be
it but nothing, last I took off the line going into the carb to see if the "fuel
screen" was clogged but nothing. What could this be, I'm thinking either the
Carb or Fuel pump...but not sure. Also that 2 week span the weather did get cold
at night lows around 26 overnite could it have cracked anything?"

 

[Haut Medoc]

Re: OMC Not running!

Welcome to iboats.......
26* is enough to crack a block or manifold.....
At this point you need to pull the spark plugs & crank the motor to see if you have water in your cylinders......
Check your oil for signs of water as well......​

 

[DenWbaseball1984]

Re: OMC Not running!

I have already checked the oil and it was fine. As far as pulling the plugs how do check for water....just pull the plugs and start it? then what should happen? But the day time highs were around 40 water ouside when I left for work would at 5am would only have a really really thin layer of ice. I had no clue that it could crack at that temp!

 

[Haut Medoc]

Re: OMC Not running!

With no anti freeze it can.....
Pull the plugs, ground the coil lead, & crank the engine.....
You'll know if you have water.....
Hopefully nothing is cracked & you can move on to further diagnosis.....​

 

[DenWbaseball1984]

Re: OMC Not running!

I know this prolly sounds like a stupid question but is there supposed to be water? And wouldn't a freeze plug blow if it was a block crack?

 

[Haut Medoc]

Re: OMC Not running!

You should not see water......
A core plug does not necessarily have to push out......
It may only be a cracked manifold.....
Or maybe not.....
However, the simple test I suggest can be performed for free.....
I'm only going by what you are telling me....
de-winterized my 1991 Forester with an I/O OMC
5.0L Cobra about 2 weeks ago, the
fist turn of the key it fired right up and ran great, I didn't have it on the
river just on some water.

This weekend I went and tried to start it again and I
couldn't get it started, finally I got it started by giving it 3/4 of throttle
while turning the key. But then when I'd back the throttle off it would die on
me, and to top it off when I did start and was running it was running really
rough! I first thought it could be bad gas from winter so I put some new gas in
and no change...

It sounds to me like something happened in those two weeks......
You need to check for water in your cylinders, ASAP......​

 

[DenWbaseball1984]

Re: OMC Not running!

Wow, I really wasn't thinking it could be that! Any other ideas out there?

 

[bjcsc]

Re: OMC Not running!

Follow Haut's advice and then post back to this same thread what you found. The first step is determining whether or not you have water intrusion. Once you let us know that, further advice will follow

 

[DukesFin]

Re: OMC Not running!

I got a cracked block 2 yrs ago... The crack was in the block and ran from one of my FREEZE PLUGS downward. Freeze plug was intact... Didn't move.

Check for water and let us know! Good luck!

 

[DenWbaseball1984]

Re: OMC Not running!

Ok another stupid question, Whats the coil lead and what should I ground it to back there?

 

[RCSConstruction]

Re: OMC Not running!

Bought a boat that had a 7" plus sized crack right between the two freeze plugs.
I am starting to wonder if freeze plugs have ever done their job?????
Good luck with the boat. I would have guessed it would it have been a bad fuel pump/filter, sounds like it may be starving. What does the exhaust look like? (smoke? white? black?) Does it pop and spit or hesitate and die?

 

[Haut Medoc]

Re: OMC Not running!

It goes from the coil to the distributer cap....
Ground it to the stud on the back of the block where the fat black wire is.......
This will require a jumper wire....
RCS, though they are commonly called 'freeze out plugs' that is not there purpose......
The 'core plugs' (or core holes) are there as part of the casting process....​

 

[DenWbaseball1984]

Re: OMC Not running!

Ok the exhaust smoke is a white smoke, and its kind of hisitating when it dies...but I also took the filter off the top of the carb and it does spit out the top of it and a little puff of white smoke comes out the top of the carb....what do you think?

 

[DenWbaseball1984]

Re: OMC Not running!

Haha...Ok Whats the the coil? I know a little about this stuff but not a lot...sorry!

 

[Haut Medoc]

Re: OMC Not running!

It is the cylindrical shaped part that the wire from the distributer cap is connected to....
At this point, if you don't know what a coil is/looks like I would have to say that you are in over your head.....
​

 

[DenWbaseball1984]

Re: OMC Not running!

Haha, There is no question I'm in over my head! But I'm always up for learning about stuff like this and getting my hands dirty and seeing if I can do it myself. Thats why I'm asking all these questions so I don't misunderstand something and do something wrong. But I'd like to try to learn some of this kind of stuff, not just take my boat to the shop eveytime that there is the littlest thing wrong with it. And the only way to learn is by asking....Thanks for all the help and bearing with me on this!! I'm going to work on it tonight I'll let you know how it goes.

 

[Haut Medoc]

Re: OMC Not running!

You might want to think about investing in a service manual......
Post back with your findings......​

 

[Coors]

Re: OMC Not running!

White smoke out of carb= timing too far advanced or cam out of phase.

 

[Haut Medoc]

Re: OMC Not running!

imported_CoorsWhite smoke out of carb= timing too far advanced or cam out of phase​

I doubt very much if either one of those causes came from sitting for two weeks.......​

 

[Gary H NC]

Re: OMC Not running!

Is it white smoke or steam? I got a feeling something cracked those 2 weeks of sitting. 26 degree temps is not good..