1980 80hp head gasket?

[bigheaded5]

Picked up a motor last week, basically free.... changed the water pump which was beyond shot..... then started it again and it ran but wouldnt idle and stalled as soon as I put it in gear. When I went around to look at the motor up close, i noticed water dripping out of the #1 and #2 spark plug areas///leading me to think maybe the head gasket is blown?

when I saw the water pump I didnt understand how it could get this bad without any damage to the motor... Im thinking it was, and it blew the head gasket. Someone told me mercurys are famous for the bolts breaking if you dont take them off regularly, and sure enough, i tried one head bolt and it snapped despite babying it. How big of a pain is changing the head gasket of a 1980 80hp inline 4 cyl. It has 145+ compression on each cylinder and runs...also has a new water pump lol

 

[bigheaded5]

Re: 1980 80hp head gasket?

OK....I broke just about every head bolt I guess its EZ out time..and thats never easy! is there a trick to breaking them lose without breaking them off?

 

[Sea Rider]

Re: 1980 80hp head gasket?

Easy as changing any other head gasket, just remove all head bolts, bang with rubber mallet head to loosen, if lower bolts are not friendly accesible to remove or torque back new head gasket, probably will need to remove complete crankcase from engine pan to work properly, clean all interior water passages, check thermo's condition. If bolts are hard to remove, some boater heats them with torch to dilate bolts threads, should come out nicely without breaking them.

Happy Boating

 

[jimmbo]

Re: 1980 80hp head gasket?

Good luck trying to change the head gasket, since there is no removable cylinder head on that engine. There is a water jacket cover that a lot of people mistake for a cylinder head. Water leaking around the spark plugs usually occurrs after the engine has run hot. Looking at your water pump, I would say it ran hot. Replacing the gasket is only temp fix as the cover has usually warped. After replacing the gasket on mine twice, I a ordered a new cover from merc and installed it dry(no gasket goo) and it never leaked again. Maybe a gengerous application of silicone sealer would work for you
If the bolts broke off at the heads you might be able to attach a visegrip to the stub and with some penitrating oil and gentle heating back them out. If not, drilling and tapping become an option. To get to the lower bolts you will probably need to move the lower cowl housing out of the way. You have already removed the back cowl support, not remove the bolts that attach the front cowl support from the front of the lower cowl housing and from the top cowl support(surrounds the flywheel. the lower cowl should now shift around enough to get at the lower waterjacket cover bolts.

 

[bigheaded5]

Re: 1980 80hp head gasket?

my 3rd attempt at trying to THANK YOU! all great tips and the pics really helpd me understand HOW water can leak form a spark plug...

Ed

 

[Chris1956]

Re: 1980 80hp head gasket?

Ed. Look closely at the block where the bolts attach the water jacket cover. Some have captive nuts on the backside of the block. some can be drilled thru and nuts used, rather than using EZ-outs. A couple of the lower bolts will need to be extracted.
BTW, the water pump area looked like a serious overheat. Did you look at the pistons/cylinders thru the transfer covers? Those bolts shouldn't break.....

 

[bigheaded5]

Re: 1980 80hp head gasket?

Thanks...and no, I didnt look at the pistons...I did a compression check and they are all 145psi and 150 psi What would looking at the pistons tell me? If they are a bit dimpled, I wouldn't overhaul the engine to be honest.... getting it at the price I did, if I cant put another gasket and replace the water jacket cover or MYBE replace the cover itself if its warped too bad...the engine is getting parted out.

Ed

 

[Chinewalker]

Re: 1980 80hp head gasket?

And there's nothing easy about an EZ-Out. Break one of those off in there and you'll never get them out. Drill & tap is the way to go, unless you've got a little of the broken bolt above the surface that you can grab with Vice-Grips. Heat and PB-blaster works wonders...

 

[jimmbo]

Re: 1980 80hp head gasket?

Not very clean in there. It looks like the bolts broke off at the heads and left you with some material to grab on to. Paitience and persistance will get them out.

 

[bigheaded5]

Re: 1980 80hp head gasket?

all 9 broke at the head..... first 4 came right out with vice grips... 2 sheered off because i drilled them for the ez out 3 lowest i cant get to very well, let them soak another night with penetrating oil....try again in the am