Mercruiser Inboard 5.7L - stalling

[nramil]

I have a 1988 Malibu Sunsetter with a Mercruiser 5.7L engine. Got the boat out of storage from the winter and at first...did not want to start up. I changed plugs, fuel filter and engine fired up fine. I warmed it up in the drive way with a water hose connected and for the first 2-3min there was somewhat black smoke coming out of exhaust and seeing a little bit of oil. After about 3mins...smoke is gone.

I took it to the lake the next day and it smoked for the first 3 mins and fine after that. Ran it about 2hrs without any issues. After that the engine with shutoff when in gear. It starts up fine and idles in neutral, but when you put in gear it dies. I took it out again the next day and same result. It smokes for 2-3 min (very minimal), works great for about 2-3hrs then the stalling starts when put in gear.

Any advice is greatly appreciated.

 

[Don S]

Re: Mercruiser Inboard 5.7L - stalling

Time to replace the lower shift cable.

 

[PSS-Mag]

Re: Mercruiser Inboard 5.7L - stalling

Black smoke is caused by rich Air/Fuel mixture.
First check flame arrestor, clean with carb cleaner.
Second thing I'd do, and some may disagree but I'd dump a can of Seafoam in the gas tank. You can get it at most any auto parts store. Run that tank through and see what happens.

I'd say likely those will fix both your problems.

The only one that confuses me is you say you see "a little bit of oil". Where do you see the oil and how much is a little bit?

 

[nramil]

Re: Mercruiser Inboard 5.7L - stalling

When on the driveway connect to a garden hose...the oil is coming out of the rear exhaust with the water. It is causing oil stains on my drive way and could see a little as the water flows down the driveway. Can the be just gunk in the water compartment of the engine?

If the carb is running rich....wouldn't cause the stalls and right away....not after 2hrs?

We are able to avoid the stalls by having the engine on neutral, rev it up, and as the idle goes back to normal idle, quickly put in gear and gas it. We can then put it in neutral and back in gear about 5-6 times with issues. After that the engine dies again in gear.