Mercury 115 water and exhaust coming out of engine cover

[Baja Boater]

I am seeing water and exhaust coming out of the lower part of the engine housing. It seems to be a vent opening at the lower part of the engine. If I put my hand over the openings . . I can see an increase in exhaust from the prop area. Also ,, the engine does not run properly .. at all .. no more than just over idle rpm. If I run the boat with the engine sheet metal cover off .. . it runs fine. I suspect the exhaust is coming back into the engine area and not enough fresh air to run at speed. Just a guess. Anyone have a clue what has gone wrong or how to fix this ?

Thanks

 

[racerone]

Start off by posting what motor you have !----Serial # and is this a 4 cylinder or an inline 6 cylinder ?

 

[Baja Boater]

Inline 6 .. 115 hp .. serial unknown at this time.. mid to late 80's engine .

 

[merc850]

Post some pics.

 

[Baja Boater]

I do not have any pictures at this time. I can say that at the rear of the engine.. lower portion of the power head near where it bolts to the lower unit .. there are about 4 or 5 openings that seem to be the only way air could get to the carbs . .. hence the guess that exhaust mixing with the air intake is causing the loss of power .. low rpms .. . i do know that jet skis will not run properly with exhaust in the engine compartment. And .. if the sheet metal is removed from this engine it runs just fine . . supporting .. at least in my mind .. the idea that exhaust is not going out the prop opening like it should .. .

Something break ... gasket failure . ? Why would exhaust and water come out in that area. Need flushing ?

Exhaust and cooling water should exit the prop opening ?

 

[racerone]

No, no-----The openings below the cowling are the exhaust relief.---Water and exhaust come out at idle so that the motor does not have to push it down to the prop.-----Perhaps plug wires are shorting to the metal cowling ?

 

[Baja Boater]

Well, that is a relief to know the water/exhaust coming out the lower part of the housing is normal. Now to figure out why the engine is not running right. It has been like that off and on for quite a while. It will run perfectly at times ,, and then .. . next time I take it out it just will not get up to speed. When it does .. it goes from 1500 or so RPM and then come alive like a shot out of a cannon. Not like a misfire . .. more like the choke is on and then all of sudden it takes off . . It did run properly with the sheet metal off 2 out of 4 times. I will keep on testing that result .. .
Thanks

 

[racerone]

There are some simple checks you need to do.------Check for spark on all leads.----Spark must jump a gap of 3/8" on them , does it yes or no ?-------You must make sure that all 3 carburetors are clean.---A plugged carburetor can destroy this engine !