HELP ! water in cylinder when cold starting

diehard

diehard

Seaman
Joined
Jun 26, 2009
Messages
58
i have 5.7 mercruiser with 4" exhaust riser my moter is 2 years old and my exhaust manifolds and flapers are almost 1 year old ..when i go to start my boat when the engine is cold if it does not start right up and have to crank it over a few times it will start to hydro lock on me pull my spark plugs and water in cyclinder ? it did it a few times last season so i replaced exhaust manifolds ..and just did it again the other day ..when running the engine runs perfect both at idle and at high rpms did compresion check and all cylinder are good ...i pulled the out drive off and there is nothing in the exhaust ports block water from exiting the boat ..when cranking it over cold it it sounds like it does starts let off the key and sounds almost like it blows up threw the carb and after that it when she starts the hydro lock ? i don't know
 
danond

danond

Lieutenant Junior Grade
Joined
Jun 11, 2007
Messages
1,118
Re: HELP ! water in cylinder when cold starting

Is the water in all cylinders or just a couple?
 
diehard

diehard

Seaman
Joined
Jun 26, 2009
Messages
58
Re: HELP ! water in cylinder when cold starting

there is a very little in cylinder's 1,2,7,8 seems to be more in 3,4,5,6 i think when it's tring to start it and almost starts i let off the key seems to turn backwards for a second [[[but not sure ]]sucking in water and thats why i get more in my center cylinders but needs some oppions and see if any one has had same problem
 
M

MercBravoIII

Cadet
Joined
Jul 1, 2009
Messages
15
Re: HELP ! water in cylinder when cold starting

Could be these possiblites, Leaking Riser Gaskets, water can be coming in thru the y pipe as well. What you should do is go to your boat pull the plugs, drain the water if any is in there, then put the plugs back in and then spray a little fog oil in the cylinders, run the motor for a little. Then after remove the plugs and be careful of the hot manifolds. See if water comes out, then go home come back next day and see if water is getting back in there. Sounds like either riser gasket is bad (Most likely) or water coming back thru the Y pipe.
 
diehard

diehard

Seaman
Joined
Jun 26, 2009
Messages
58
Re: HELP ! water in cylinder when cold starting

i have pulled the plugs before i even try to sart it and are dry with no water in cylinders i get water in after i crank it over a few times when i hear it fire i let off the key and it like desiel's for a second and stalls then i crank it over again in it starts to get water in cylinder's and pull my plugs and there is now water in cyclinders ? ? ? ?
 
You must log in or register to reply here.
Top