Water Leaking from The spark Plug

[Flyingchef84@gmail.com]

Hello I have 1977 mercury 200, 20 hp. Somehow water come out dripping like leaking come out from The spark plug, is this normal ??? or my engine is damaged ? Engine is still running though...Thank you for anyone help.

 

[oldman570]

Re: Water Leaking from The spark Plug

Water dripping from around the spark plug happens when the water head jacket gasket is bad. That motor dose not have a removable head and that part of the motor is casted in one pice. You can replace that gasket by removing the water jacket plate and cleaning the mating surfaces and make sure that the parts are straight and not warped from a overheat of the motor. The bolts that hold the plate on can be very hard to get out because of corrosion and can break off and this will cause a BIG problem of they do. If they are corroded you will have to go very slow and use heat and power blaster to get them out. If they do not want to turn , you will have to heat, soak, and tap them till they will turn without breaking off. The other option is to take it to a shop and have them drill them out and clean up the threads, which can be very costly, or run it the way it is and try to repair it over the winter months. JMO
Oldman570

 

[dwco5051]

Re: Water Leaking from The spark Plug

Hello I have 1977 mercury 200, 20 hp. Somehow water come out dripping like leaking come out from The spark plug, is this normal ??? or my engine is damaged ? Engine is still running though...Thank you for anyone help.

Gasket probably leaking on the cylinder block cover. No your engine is not damaged. An easy fix if all the bolts are not badly corroded.

Oldman is spot on. He must have responded while I was still typing

 

[wired247]

Re: Water Leaking from The spark Plug

Take it to the machine shop? To get broken bolts out? Or you could just centerpunch the holes ( use a transfer punch the size of the covers bolt hole opening ) and then drill the bolt out. Those cover bolts are grade 2 bolts made out of cheese whiz. They drill easily. Then use an ez out. That works 1/2 the time. When it still wont come out drill it oversize and use a helicoil or your favorite other thread insert. No need to remove the block for something simple like that. Only time you'd need to pull the powerhead is when its one of the lower bolts under the lower cowling that you can't get a drill at. Don't replace the bolts with stainless bolts. They are even cheese whizier than grade 2.