89 40hp evin head removal question

[wetboy86]

I have 2 bolts that sheared off but careful worked 8 out. This head is so stuck I cant budge it. I have repeatedly soaked it with kroil, smacked it with a mallet put some wedges behind it left under tension all night. and went at it again this morning and still cant crack it open.
Did I miss something here? I am going to try a heat gun next I guess. Trying to be patient and not break anything in case the motor can be saved.

 

[wetboy86]

Re: 89 40hp evin head removal question

still bump

 

[Tim Frank]

Re: 89 40hp evin head removal question

Gotta love that salt water....
Did you try putting the plugs back in and turn it over a few times?

 

[wetboy86]

Re: 89 40hp evin head removal question

Tim, yes I have tried that with no success. It's like I am missing a bolt some where.
I am now in my 3rd day trying to get this thing off.
I have drilled the broken bolts down as far as I dare, hoping to have some left to help remove them from the cylinder. Filled the holes with Kroil and let it soak all night. It looks like the dry white powdery stuff on the head bolts has the bolts welded to the head. You would think the Kroil would eventually get to this stuff.

boaters have a love / hate relationship with salt water.
I am in the hate phase right now.

 

[AlTn]

Re: 89 40hp evin head removal question

checking the shop2.evinrude.com site for the 1989 40hp.....it looks like you have 12 head bolts...2 of which are at the very bottom?...have you removed them?

 

[wetboy86]

Re: 89 40hp evin head removal question

It's only 10. I looked at that diagram there are what looks like 2 water passages at the bottom. The holes do not pass through the front of the head. If you take the head bolt part#
and look at the chart it shows 10 needed also. Thanks for looking and trying to help.

 

[mikesea]

Re: 89 40hp evin head removal question

The reason why they snapped is due to the grab the head has on them.thats why it wont pull off.First,heat is a friend here,anytime you have a stuck bolt ,use some heat.Get a hand held bottle of MAPP gas with a electronic igniter.The whole setup is about 20 bucks at any large homecenterAt this point ,if possible heat the head around the bolt ,NOT the bolt or bolt hole,you want to expand the alum.after its good and hot do some tapping ,trying to free the bolt from the salt that is what has gotten in there.Hard to believe ,but Ive lifted boats on trailers trying to pull powerheads stuck by a couple bolts.You want to avoid ruining the block,that head needs good material for a good seal,and the block has water passages you can actually break off .Find a raised cast mark ,or sometning you can hit with a blunt chistle ,tapping with a hammer ,the idea is VIBRATION more than trying to slide head off the broken bolt.If you have access to a air operated chistle ,that can help with the vibration,you may just work it back and forth ,up down ,heat always.A last resort is the distruction of the head ,you can cut a relief slot around the alum holding the bolt.Might get a replacement head on ebay.

 

[wetboy86]

Re: 89 40hp evin head removal question

Thanks Mike
I have been very careful so far, but I have pushed the limits on the tapping and drilling.
I know getting impatient with it will destroy it. Mike I believe you could lift this whole boat and trailer by it and not budge it. Heat is defiantly the next thing I need to try, I can't go no farther with what I have here. Unfortunately I have to pause for a trip. I will post the results when I try it. Anyone else chime right in.
Thanks guys for taking the time to help.

 

[wetboy86]

Re: 89 40hp evin head removal question

OK here's an update, I finally got the head off, 2 weeks of soaking it in Kroil I went out there determined to get it off if I had to sacrifice the head. I pounded it off with a big hammer and some wedges. after the head was off the bolts backed out easily with vise-grips. It had a blown head gasket. So on with a new gasket, resurfaced head, thermostat and a water pump kit. The head bolts cost over 11 dollars a piece, that's just crazy. Now the bad part, i just put the water on it and tried to start it....NO SPARK!
Man can I catch a break here?

 

[wetboy86]

Re: 89 40hp evin head removal question

Put some new plugs in and it runs. needs some adjustments, but seems good.
Now it leaking water at the exhaust cover, where a "marine mechanic" twisted off two bolts.
awesome

 

[wetboy86]

Re: 89 40hp evin head removal question

motor ran good and then reverted to one cylinder, limped back from inlet, compression test bad on one cylinder low on other. took it to local marine shop, after tare down owner said he had never seen one of these motors so wore out. so bad I had to buy a crank and he donated some used cases. I cant complain, I did run the heck out of it for 5 years. 2 of those years everyday. Got it back and I cant believe how quiet it is! It now idles in gear for long periods. I am back in action with the old 89

 

[kbait]

Re: 89 40hp evin head removal question

Did you ever de-carb your motor in those 5 years (or add seafoam to fuel)? I yearly decarb my heavily used 15hp and I'm wondering if I'd have your end result if I never decarbed at all.