3.0 mercruser wont start after stalling

[Bfoster22]

Hi i purchased a 1986 4 whinn with 3.0 mercruser i/o. I replaced battery, plugs, cap, rotor, points. Originally had no spark. Drained fuel tank has new gas. Took this out twice ran great started fine. Last trip it was bogging down and stalled and now wont run. Still has spark sounds like it wants to start but wont. When working throttle fuel does squirt into carb. Any ideas? Thanks.

 

[Bondo]

Ayuh,.... Welcome Aboard,.... Sounds like crud in the fuel system,......

Are the filters clean,..??

Is the tank givin' up it's load easily,..??

 

[Bfoster22]

Hi, i took 15 gallons of old fuel out and put in new. Ran perfect for 2 days. The filtwr at carb is spotless the one on the pump wasnt bad but i cleaned it. I also sprayed statting fluid in carb and nothing. Has spark looked week so i read something about bringing 12v to coil and it started. Took of wire now uts still starting and running? Bad coil?

 

[kenny nunez]

If it s a breaker point system. Get a Test light or a volt meter, connect it to the + or bat side of the coil, have some one turn the key and see what you are getting. If there is 0 or very low 1-4 volts the by-pass circuit is not working. There should be a wire on the "R" or the @ 2 o'clock on the starter solenoid. Sometimes the booster solenoid does this but most inline engines it is on the starter. If that circuit is good make sure that the points and condenser are not any of that junk from those big box stores. NAPA or a marine dealer. Better yet if is is a point system convert it to a Petronics. It just depends on what you have.

 

[Bfoster22]

Update- replaced coil and still nothing. Got plug wires for an automobile and it runs now not great. Probably because there not the right wires?

 

[Bondo]

Ayuh,.... Fresh gas in an ole fuel system fulla crud, still has crud in the system,....

Yer symptoms say a lack of fuel flow,....
Did ya check the filters for crud,..??

If it don't have a canister type fuel/ water separator fuel filter,....
Ya oughta Add 1, 'tween the tank, 'n fuel pump,...

 

[Bfoster22]

I checked the.filter at the carb and its clean. The one in the pump isnt bad either. There is not one in the line. I got some new plugs and a can of motor tune to spray in carb to try.

 

[Bfoster22]

So. Spent more time today. Carb is getting fuel. Sounds wierd but if i adjust the points it starts and runs for about a minute everytime. Then nothing. Adjust points again and the same. These are new points. Could they be bad?

 

[Bfoster22]

Hi everyone. Found out the new points wer bad. Runs now. New issue is it runs great for a while , then bogs down. After sitting a while it runs good for a little bit then bogs down again? Please help just want to enjoy this boat lol.

 

[89Galaxy]

Hi everyone. Found out the new points wer bad. Runs now. New issue is it runs great for a while , then bogs down. After sitting a while it runs good for a little bit then bogs down again? Please help just want to enjoy this boat lol.

I have a 3.0L which done the same thing before Blowing a rod, bought another rebuilt one. Did you check the oil for any signs of water, it will look white and creamy.

The first thing you need to do with and old engine is take the exhaust manifold off and replace the gasket along with the riser gasket (the elbow coming off the top).

Check for any signs of water leaks!

Those gaskets only cost about 20$ and you MUST do it or your engine is a ticking time bomb anyway.

My engine right now has an exhaust leak and it lost power, If your engine has an exhaust leak it will lose half its power or more and you will here a tick tick tick sound coming from around the exhaust manifold.

 

[Bfoster22]

No water on oil. Manifold not leaking. Thinking its a fuel issue. Maybe vapor locking.

 

[89Galaxy]

No water on oil. Manifold not leaking. Thinking its a fuel issue. Maybe vapor locking.

If you havent changed those gaskets you better! Or you will be regretting it dearly later!

 

[89Galaxy]

No water on oil. Manifold not leaking. Thinking its a fuel issue. Maybe vapor locking.

IT can have an internal water leak that you wont be able to see without taking the manifold off. This was my first mistake when i bought my first boat. I didnt see any leaks external to the engine. Since you have to change those gaskets every few years its a good idea to do it anyway then you will know if any water has been leaking into the cylinder head causing rust or vapor lock both can cause the engine to run very badly like it has a blown head gasket.

 

[89Galaxy]

No water on oil. Manifold not leaking. Thinking its a fuel issue. Maybe vapor locking.

Once you get the manifold off the torque specs are 23 pounds if you have a 3.0L, takes about 20 minutes... is really pretty easy. make sure you get a riser gasket as well because they usually break when you take the riser off if its old the gasket will be stuck on there and probably tear when you pull it off.

After running it for a few hours and getting it hot make sure to torque it again!

This is where i get my stuff: http://www.*****************/parts/me...-thru-0c856558

they ship pretty fast.