Mill heads?

[fishnfool15]

Hello fellow iboaters. I have a 1989 Evinrude 110Hp that has been overheating. I pulled the heads to inspect the water deflectors and sure enough they were melted. This was after replacing the thermostats and water pump. My question is do you recommend to mill the heads before reinstalling? What do the pros recommend to clean the surfaces of the head and block before reinstalling? I've seen alot here posted about using sand paper on a glass surface. I'm no professional mechanic, however I would never do that with any heads I pulled of my Chevelle.
Any help is appreciated!

 

[emdsapmgr]

Milling the heads infers that you will be removing substantial material from the face of the head. I don't think that's what you mean to do. Planing the heads is a truing operation that basically makes them flat with minimal material removal. You may find that you need to plane them. First, I'd suggest you try them as is with a new set of head gaskets. If they seal (make good compression) and don't leak water, you are in business. If you find water leaking from the heads or find water intruding into the combustion chambers, then get them planed smooth. If you do it this way, you are at risk for a second set of head gaskets. If everything turns out ok with just the first set of head gaskets, that's all the better.

 

[racerone]

Using emery cloth and a glass surface is the procedure recommended in the factory service manual !!!------All the heads on a motor like yours are warped after 20 years of service

 

[fishnfool15]

Thank you for your replies. You are correct that I meant planning. How would you go about removing a bent bolt from the head? The head is off but while loosing this bolt out it also brought the head with it from the block. The end result is the bolt remaining in the hole and I'm unable to get it out. I've tried lubing it up, I also don't want to damage the head itself. So I have avoided pounding on anything as of yet. Having problems posting a pic of it.

 

[emdsapmgr]

You could try a set of good vise-grips. Or, weld a nut onto the stub end of the bolt and turn it out.