96 Mercury 115 Head Cover Cracked

[birddog58]

I am looking at purchasing my freinds 17' Mako that has a 115 Mercury on the back. The boat has sat for about a year and a half an not ran, it fired right up the other day but noticed water coming out from the cowling. The noticed there is a crack in the head cover at the bottom cylinder, I figured water froze while it was sitting and cracked. Needless to say I am worried about snapping all 18 bolts around the cover my question is are there any alternative ways to fix this without taking the cover off if not are there any tricks to removing the bolts without them snapping. I have been soaking them in kroil for about a week and figure a little tapping on the heads and some heat. Any help will be much appreciated

 

[Laddies]

Re: 96 Mercury 115 Head Cover Cracked

Let him have it fixed

 

[birddog58]

Re: 96 Mercury 115 Head Cover Cracked

Our local and only Mercury dealer is $$$$$$$$ and does not have great reviews by the community. I have plenty of confidence in replacing the part and have tackled way worse and more difficult jobs than this, just looking for a little insight from those who have seen and fixed this problem before I get started.

 

[Laddies]

Re: 96 Mercury 115 Head Cover Cracked

The engine should self drain so it should not freeze, about a month ago there was a fellow on here with a 6 cyl 115 that acted the same as this one but when he removed the water jacket cover he found that the end of the cyl had broken off, anything is possible. If you fell that you must get involved use a small impact and work the bolts back and forth to remove them.

 

[Rxracer]

Re: 96 Mercury 115 Head Cover Cracked

I just got done fixing mine on my 95 115. In the process I broke off 9 bolts, and had to dril and tap them all. It wasn't real bad took me about 3 hours or so to do the drilling andtapping.
My gasket started to leak at the number 2 spark plug.
When i reassembled i used some hardened 8mm stock and made studs and re did the whole head cover with studs so i wont have to deal with the corrosion inside again
Rob

 

[birddog58]

Re: 96 Mercury 115 Head Cover Cracked

I am going to go take it off this afternoon, I am praying there is no engine damage Laddies has got me worried now. I will let yall know what I find. Thanks

 

[birddog58]

Re: 96 Mercury 115 Head Cover Cracked

Well cover is off and there is no other damage:joyous: still not sure why it cracked, I can tell that some on had it off in the past though, I just wish they put antiseze on the bolts. I did manage to break off six bolt in the powerhead, my question now is, luckily there is 2-3 threads sticking out of the hole, do I risk frying any electricals if I weld a nut to the broken off bolts

 

[Rxracer]

Re: 96 Mercury 115 Head Cover Cracked

I tried the same thing. Welding nuts heating and cooling with wd40, everything. Just take off the plate on the right that has youe coils and stuff so you don't burn that up and i would also remove the temp sensor.
I think that whole process worked for like 2 of mine. I was pretty good at center punching and drilling by the end of the night though.
Rob