90 hp broken bolts

IkoN

Cadet
Joined
Jun 25, 2008
Messages
12
I have an 86 johnson 90 hp. while taking off the exhaust plates broke a few bolts. I have room to grab but heat and vice-grips are doing in.any suggestions?

there are 4 out of 25 broke. 2 out of the 4 are next to eachother!

Thanks,
Joe
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: 90 hp broken bolts

You need intense concentrated heat, such as an acetylene torch. Careful you don't melt it though. Takes practice.
 

hawkman222

Seaman Apprentice
Joined
Feb 20, 2006
Messages
45
Re: 90 hp broken bolts

I'm with F R. Lots of heat and patience. Just try to get them to move by wiggling at first before trying to turn them out. I would NOT recommend the use of easy-outs. They're as likely to break off in the bolt as they are to remove it and once you break an easy-out off in a bolt, you've just about eliminated any chance of trying to drill and tap.
 

KYLakebasser

Cadet
Joined
Mar 16, 2009
Messages
10
Re: 90 hp broken bolts

If you have the powerhead off, and can lay it flat, try some PB blaster and peck on the bolts lightly with a hammer , as you spray the agent. I've had amazing results with the blaster . It doesn't work as well, if the blaster doesn't sit around the bolt long enough to penetrate, then the heats the answer.
Good Luck ,
basser
 

tx1961whaler

Vice Admiral
Joined
May 31, 2008
Messages
5,197
Re: 90 hp broken bolts

And when you drill out the bolts, here's a hint:
Screw the exhaust plate back on to use as a guide to drill them out straight.
Also cobalt bits are great. Left-twist cobalt bits are better (run the drill in reverse.
I broke a bunch off flush to the head last year on my 40. No fun, but I got them all drilled and tapped OK.
 

Robj

Lieutenant
Joined
Mar 22, 2007
Messages
1,441
Re: 90 hp broken bolts

One way that I have removed broken bolts is to take the same size nut, screw it onto the remaining part of the bolt, and then get the stick welder and weld the nut onto the bolt. Gets it real hot and I have had a success rate of about 75% with this method. Sometimes you have to do it more than once.

Whatever you do, stay away from the easy outs. My experience is they tend to break and then you will have a very difficult time drilling them out.

Good luck
 
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