omc cobra 5.0

[jmorgan7988]

hello I have a 1994 chris craft concept 197 with the 5.0 omc cobra h.o. carburated engine boat sat for over a year at shop while outdrive was being replaced ran fin when parked.... now tried to get this thing ready for the water and it turns over but will nt start so far I HAVE REPLACED all spark plugs installed new coil upgraded to electric fuel pump added new battery and installed new roto button and distributor cap but still nothing.. It has spark its getting fuel but just will not start any ideas are appreciated??????

 

[alldodge]

Howdy

If it was getting fuel and spark the motor would run. How do you know its getting fuel and spark?

Does your gas smell like gas? Take a rag stick it in the throat of the carb and pump the throttle, pull it out and smell it

 

[jmorgan7988]

pulled # 1 plug out used plug and boot against metal while trying to crank to check spark it honestly seems like its turning over rather slow to me like there is a saftey switch not letting it fire or something but idk

 

[alldodge]

Put a meter on the battery and start cranking, it should not go below 10V and a good battery should stay above it

 

[jimmbo]

It sat for over a year, I doubt the a stabilizer was added to the fuel system prior to it being taken to shop? Does it start if you spray a little gas into the carb? Is the choke closed?

 

[jmorgan7988]

NEW battery and new fuel out of a gas can did not want to attempt using the old fuel

 

[alldodge]

With it cranking slow you might still have a starter or corrosion issue. The motor needs at least 300 rpm to start.

Your using a new can of gas and are you sure the new fuel has made it thru the filter and pump to the carb?

 

[jmorgan7988]

yeah new starter and gas is going into carb and I see it going in I have 12.3 volts at battery and 12.3 volts at starter solenoid where else should I check? also you had mentioned corrosion? as in on some of the terminals some where?

 

[alldodge]

Is that 12.3V while cranking, or just sitting?

If its 12.3 cranking and it still cranks slow I would check compression. The reason to check compression is so you can tell the health of the motor and also get a look at what the plugs look like

The corrosion was if your battery is fully charged and it cranks slowly, need to check connects because corrosion will reduce speed of the starter

You have spark, you have fuel, engine is cranking there should be something firing even if its a backfire. Something is not adding up

 

[jmorgan7988]

I will check shortly about the voltage while cranking that was a reading while nothing on

 

[vasy]

Try adding some fuel directly into the carb from a cup or a bottle, maybe an ounce or so and see if you get any action, try cranking 2-3 times.
This way you are 100% sure on the fuel in there, no matter what other car/fuel issues can be in the way.

 

[jmorgan7988]

ok will do thanks... I will update soon

 

[jmorgan7988]

Okay added fuel directly to carb still nothing

 

[HT32BSX115]

Okay added fuel directly to carb still nothing

No spark. Pull the plugs and hook them back up to their respective wires, lay them on top of the engine and see if they spark when cranking

 

[jmorgan7988]

will pull all the plugs once again and insure there all getting spark also is there any easier way or tool to remove plugs on this particular motor without having to remove manifolds? I can get to 1&4 and 5&8 just the middle ones I cant get too

 

[HT32BSX115]

is there any easier way or tool to remove plugs on this particular motor without having to remove manifolds?

Only if you can find a short(er) (deep) socket and/or use either a U-joint or other swivel joint to loosen the plug. Otherwise, you're stuck pulling manifolds.

If you have already previously inspected your plugs, you could use a set of new plugs to do the same thing without removing the existing ones. But if you haven't looked at those plugs in a while, it might be a good idea to do it now.

 

[67stanger]

Had kinda same issue on my deckboat. My was the safety switch by ignition and is the coil grounded in the hold down? On spark plugs used a open end wrench you can try and use a socket with a swivel but may crack spark plugs.

 

[MasterGoa]

These are your friend!

http://www.alltradetools.com/catalog/1667-1703-large/643002-3-8-dr-5-8-u-joint-spark-plug-socket.jpg

 

[jmorgan7988]

ok still have no clue have had several car enthusiast look at the boat and cant figure it out still have fire on all plugs good fuel good everything lol still will not run is it possible to be some type of safety switch other than the kill switch that could be bad?

 

[HT32BSX115]

still have fire on all plugs good fuel good everything lol still will not run

So all 8 spark plugs are "sparking"? when you crank the engine?