Busted bolts on BOTH cylinder head covers 1987 EV 90HP

[bang4dabuck]

Tried to get an easy out on there but hard to drill a deep enough hole to get screw extractor in (1/4" x 20 bolts). I was thinking to remove both cylinder head covers so as to maybe be able to catch enough of the bolt with some vice grips.
But there could be a CATCH 22, if they are still THREADED on to the CYLINDER HEAD COVER'S themselves, I won't be able to remove the covers anyways.

Any ideas as to what kind of drill bit can penetrate those bolts to get extractor in ? I was using a titanium bit, very slow going.

How about the cylinder covers being threaded, are they ?

Anybody here been through this situation ?

thanks

 

[rodbolt]

Re: Busted bolts on BOTH cylinder head covers 1987 EV 90HP

DO NOT use an easy out.
your next post will be about broken easy outs.
simply use a bullit point type bit,Dewalt makes nice ones, about 7/32 and drill and retap.
mess up and you will helicoil it.
not hard but the helicoil kit is about 50 bucks.
the bullit point style bits wont walk as long as you hold it and start it straight,
do it all all time here in the salt pond.
\

 

[ezeke]

Re: Busted bolts on BOTH cylinder head covers 1987 EV 90HP

The 10 large cylinder head bolt holes are not threaded where the screws pass through the head, and the OE shoulder screws are not threaded in the area that passes through the cylinder head.

However, the corrosion that often binds the screws is often in that area. Some heat may break the corrosion.

 

[bang4dabuck]

Re: Busted bolts on BOTH cylinder head covers 1987 EV 90HP

These are NOT cylinder head bolts but the cylinder head COVER bolts. There are 16 per cover(14" x 20).

Anybody know if the cover is threaded or just pulled tight by threads on cylinder head itself ?

 

[ezeke]

Re: Busted bolts on BOTH cylinder head covers 1987 EV 90HP

The same, but they are much easier to break. Why are you removing the water covers?

I use left handed drill bits - start small work to larger size. The broken screws usually come out with a little heat once the cover is out of the way.

 

[bang4dabuck]

Re: Busted bolts on BOTH cylinder head covers 1987 EV 90HP

Putting cylinder head temperature senders on.

Are you saying the bolts do not thread onto the cover?

Are "left hand drill bits" the same as "screw extractors" ? If so that is what I'm trying but I need a drill bit that can get in there. Know of any ?

 

[Daviet]

Re: Busted bolts on BOTH cylinder head covers 1987 EV 90HP

The bolts are not threaded into the covers. Left hand drill bits are not extractors, the turn the opposite way and will some times remove broken bolts by drilling them out.

 

[bang4dabuck]

Re: Busted bolts on BOTH cylinder head covers 1987 EV 90HP

Good !!! That means I have 2 other options but I'm just skeptical of any bits burrowing in as hard as I've tried.

Taking everything apart to get them covers off isn't a piece of cake either. Watch me break a couple other bolts doing it.

 

[F_R]

Re: Busted bolts on BOTH cylinder head covers 1987 EV 90HP

You think you got troubles? Take a look at this one that I am working on. I had to drill 8 of the bolts out of the head to even get it off. Still have to get them out of the cyl block. All in a normal day's work for an outboard mechanic. Are we having fun yet?

 

[tx1961whaler]

Re: Busted bolts on BOTH cylinder head covers 1987 EV 90HP

Good !!! That means I have 2 other options but I'm just skeptical of any bits burrowing in as hard as I've tried.

Taking everything apart to get them covers off isn't a piece of cake either. Watch me break a couple other bolts doing it.

A set of good cobalt bits with real cutting fluid will easily drill through anything on an outboard. Listen to the advice about the EZ outs. They are really not made for getting out heavily corroded bolts.