merc 650 water around spark plug

[jbrown909]

i have just purchased a late 70's early 80's boat with a merc 650 65 h.p. upon inspection with the cover off the engine and running there appears to be water coming around the top spark plug. i ran the motor for about 30 min. and it did not seem to overheat. there is also a small hole next to the plug that is leaking as well. is this normal? do i have a bad gasket or possibly a cracked head? the person i bought it from said the water pump went out awhile back and the motor did overheat. he replaced the pump and ran the boat for 2 more years without knowledge of the leak. if i do not fix asap will i blow my motor. first boat very excited to get it wet. thanks for your help

 

[Clams Canino]

Re: merc 650 water around spark plug

That "head" is just a water jacket cover. The fact that it's weeping is proly non-consequential. Try to seal the leak from the outside. Romoving that plate can often lead to broken bolts and a real hassle.<br /><br />-W

 

[Texasmark]

Re: merc 650 water around spark plug

And if it is just a little leak, your water jacket must have a hole in it; could be from corrosion. Any leaking water would drain out of the engine and since it is small, as Clams said, tain't hurting anything and anytime you go into somehthing you always stand a chance of making a bigger mess than you had when you started. <br /><br />Mark