Mercruiser 350 Horizon MPI closed system

[blueman330]

I was out Saturday 2002 342 Rinker with 6 people trying to get on plane the starboard engine started poping and then diesled and died and we got back washed,,,,,, could not restart. Prior to going out had to jump the selinod to start thought that was the problem. Pulled the starter and bench tested fine, replaced selinoid and then my friend suggested turning the crank which was very difficult which lead to checking the plugs. Removed plugs found equal amounts of H2O in each cylinder, no water in the oil. Called Mercruiser to check on bulletins and was instructed to spin the motor to get the remaining H2O out spray some oil spin again and install new plugs, valves may have been open when hit with the back wash...Any other advice to determine if this occurance is going to lead to another disaster,

 

[HT32BSX115]

Re: Mercruiser 350 Horizon MPI closed system

I was out Saturday 2002 342 Rinker with 6 people trying to get on plane the starboard engine started poping and then diesled and died and we got back washed,,

Howdy,


Engines don't "diesel" at high power settings. In fact, they only "diesel"when you shut them off. [UNLESS IT'S A DIESEL!!!]


If it started PINGING badly, I.E. DETONATION at FULL throttle (which is near where you would be if trying to get on a plane), you may have SEVERE damage to one or more pistons and /or valves!

After you pulled the plugs and cleared the water, you should probably do a compression check to see if you have (close to) zero compression on one or more cylinders.


Sorry about that,


Rick

 

[Bondo]

Re: Mercruiser 350 Horizon MPI closed system

Ayuh,....If this is Saltwater,+ it hasn't been spun, 'n oiled,.... It's probably already too late...

I agree with Rick,.... Detonation is a Sure Killer, in a very short order....
Probably went Lean,+ Smoked it....
The compression test is the 1st diagnostic step...

 

[blueman330]

Re: Mercruiser 350 Horizon MPI closed system H2O Injestion

Re: Mercruiser 350 Horizon MPI closed system H2O Injestion

I'm praying this is not the case, will check compression and get back....Thanks!

 

[rodbolt]

Re: Mercruiser 350 Horizon MPI closed system

leaking risers or manifolds will do that exact symptom.