Merc 5.0 won(39)t turn over.-gctid811583

[Chapman]

Hey guys, My boat has been giving me trouble with stalling out at idle and acting sluggish when accelerating. First thing we did was rebuild the carb and that didn't fix anything. We then popped off the distributor cap and saw it was in bad shape so we replaced it and it ran like a champ. That was 3 days ago. We went down today and it started right up, ran for 3 seconds, and died. Figuring the carb was flooded I let it sit for a while and it fired up. I ran the rpm's up to 1500 to make sure it wouldn't die again but it did anyway about a minute later. Next step was we replaced the wires and pulled the plugs (which are from last year) out and regapped them all and after that I shot starter fluid down the throat of the carb and it won't even cough. It has fuel and spark. The spark is orange and doesn't look good. Could a weak coil be the cause of this problem ? Any other things I should be looking for ? I was all over the engine doing the plugs and wires so maybe I knocked something loose ? It is getting spark though. I talked to 3 mechanics and they're stumped. Going back down there in the morning so any ideas would be very useful.

Also, it's been raining a lot the past few days and I didn't have the cover on. Water did make its way down on top of the backside of the engine. Exactly where the distributor and ignition coil happen to be. Popped off the distributor cap and it was damp so I dried it off and popped it back together.

[builderdude]

So it currently won't turn over OR it currently will turn over but won't fire off ?

If she cranks (turns over) then it's either fuel or ignition. You say the spark doesn't look right so it could be a bad coil. You say it's getting fuel, can you see it squirt down the throttle bores at the carb when someone operates the throttle? If so are you sure it's fuel and not water (as in rain water got in the fuel tank) A shot of starting fluid down the carb could help verify.

Flame arrestor on, blower running and fire extinguisher near by when messing around with gasoline in the engine bay!

[Chapman]

Yes the starter is spinning the motor and it won't kick over.

Yes I can see what appears to be fuel shoot out when the throttle is engaged.

I did try starting fluid to no avail. I didn't have somebody with me at that point so I shot it in and then hit the ignition maybe a second or 2 later. I will try gas in the morning.

I'm going to swap out the fuel water separator in the morning and pour the contents into a glass jar to examine the fuel.

[Ruffryder]

So she is cranking, but not firing.

Could be the kill switch...

With the ignition switch on, check for power at the ignition coil.

[Chapman]

Thanks for the tip ruff. The only kill switch I know of is the one by the throttle. Are there others ?

[Ruffryder]

No
..........

[Apurpura]

If you suspect the fuel, I would bring a portable fuel tank and have the fuel line going to that just until you rule out bad fuel in the tank. I see my mechanic do that on all the boats he works on. He says he never trusts the fuel in the tank. He has been in business for 25yrs and has saved people some expensive carb rebuilds when they don't need them. Since you are going to be replacing the filters anyway just just plug the line coming from the tank and have the line come from the portable tank into the fuel filter on the boat. How old is the fuel in the boat? I just had to drain the fuel from my boats tank, yuk the junk that came out was incredible. I got 20' of clear hose from a hardware store so I saw all the garbage that was coming out.

[landrover]

Sounds as if its electrical. Is it thunderbolt 4 or 5? Would be looking at the distributer pick up and a new rotor arm as they break down occasionally and the rotor arm is glued on and normally gets destroyed removing it.

[Chief_Alen]

What year and make of the engine ?

Freekin getting tired asking, it makes a difference !

[Chapman]

I'm sorry it's a 2007.im not sure what you mean by model but it has a alpha one outdrive if that helps.

[builderdude]

2007, model of boat (i.e. 2455 etc. ) 5.0 alpha one.

[Chief_Alen]

Starts runs 3 seconds, fuel pump.

Put straight power to the fuel pump from the battery see if the engine runs good.

Post back !

[Chapman]

It appears that the problem was the ignition coil. First I swapped out the fuel water separator and dumped the gas into a glass jar. Gas was good. Next I swapped out the ignition coil and then sprayed ether down the carb throat. I had it at full throttle when I cranked it and it fired instantly. Ran like a champ all day so I'm very happy. Thanks for the help fellas.