Blow-by on 1988 Mercruiser makes engine stall

[JohnCiccarelli]

Re: Blow-by on 1988 Mercruiser makes engine stall

Well the valve covers are back on and the blow-by is still there. Is there anything left but rings? I guess the motor is coming out.

 

[Yepblaze]

Re: Blow-by on 1988 Mercruiser makes engine stall

Blow by is the result of combustion gasses blowing by the pistons.

New heads can just exacerbate a blow by condition, due to improved valve sealing.

Take it apart further this next time.

You will probably need to remove the motor crankcase assembly from the boat.

They used to sell some magic pills that would fix it, but I think it was a scam.

 

[JohnCiccarelli]

Re: Blow-by on 1988 Mercruiser makes engine stall

The Motor is back in and all seems fine. The Blow-by is gone. The maiden voyage is tomorrow.

Thanks for all of the support.

John

 

[nola mike]

Re: Blow-by on 1988 Mercruiser makes engine stall

what did you end up doing?

 

[CaptainHook]

Re: Blow-by on 1988 Mercruiser makes engine stall

Did you do a bottom end rebuild????

 

[JohnCiccarelli]

Re: Blow-by on 1988 Mercruiser makes engine stall

Complete rebuild. Needed to bore .030 over. 3 of the pistons had rusted rings.

 

[robjen1019]

Re: Blow-by on 1988 Mercruiser makes engine stall

by those compression number, it looks like a blowout of the head gasket between the middle 2 cylinders.

 

[fishinpa]

Re: Blow-by on 1988 Mercruiser makes engine stall

Once again a wet test when checking compression - as a few had mentioned ,
would have saved you a lot of extra time and effort ..

rebuilt now so good luck hope she runs well for you !

fish