Single bolt rusted and not budging on cyl. head- suggestions on how to remove??

[kippstakes]

I need to replace the head gasket and rings on my 72 Evinrude 50hp but am unable to get one of the bolts out- seems to be rusted in place or something.
Any tips on how to budge a locked bolt??

Thank you

 

[boobie]

Re: Single bolt rusted and not budging on cyl. head- suggestions on how to remove??

First spray it with PB-Blaster and leave it sit. Then give the bolt head a few raps with a hammer. Next apply some heat around it, put a socket on it and rock it back and forth. The more heat the better. I'm sure you'll get more opinions.

 

[alldodge]

Re: Single bolt rusted and not budging on cyl. head- suggestions on how to remove??

Agree, Blaster, heat and a hammer. Apply Blaster, heat then hit it with a hammer straight down on top the bolt. If it does snap off, will need a welder, washer, nut and wax.

 

[racerone]

Re: Single bolt rusted and not budging on cyl. head- suggestions on how to remove??

Do you have the powerhead off the exhaust housing ?-------If it is a head bolt then drill the bolt head off.---Now remove the head.----You now have a stud that you can grab.--Heat the block and the stud should come out.

 

[kippstakes]

Re: Single bolt rusted and not budging on cyl. head- suggestions on how to remove??

Thanks for all the advice. Time to break out the soldering gun I guess.

 

[oldboat1]

Re: Single bolt rusted and not budging on cyl. head- suggestions on how to remove??

Kippstakes -- don't think a soldering gun is enough, but maybe. If it's the last bolt, can you move the head a little bit to loosen the stuck bolt? Lightly tap the head sideways around the perimeter using a piece of scrap wood and hammer. If you can get any slight sideways movement around the bolt it might be enough to break it loose.

 

[jb93]

Re: Single bolt rusted and not budging on cyl. head- suggestions on how to remove??

As Boobie stated...with some additional detail.

I had success using propane torch and compressed air can hot and cold cycles (as recommended in my thread by High Trim here on this forum). I heated the end of the bolt head directly with propane for about one minute, then turn compressed air can upside down and spray it with cold blast (must hold can upside down). I did 3 cycles like this. Then I heated the bolt heat for one minute direct heat and then moved the heat to the block and heated around the bolt threaded area - kept the heat moving when on the block around the bolt - again for about 1 minute. My theory was as the bolt as cooling (shrinking) I was expanding the bore by heating the block just around where the bolt screwed in. Keep in mind...there are no threads on the head cover, you have to heat the block area to expand the threads. See attached....heating the block behind the head gasket...not the head as it is just smooth bore hole through the head with no threads.

Used my socket wrench and tightened it first (just got a real slight turn), then loosened it (again slight turn), then tightened, then loosened...did this back and forth routine loosening just a little bit more each time until I got one full rotation...then was able to back it out.

I used Liquid Wrench spray as described above to soak. PB Blaster...same...same.

Be Patient.

 

[oldboat1]

Re: Single bolt rusted and not budging on cyl. head- suggestions on how to remove??

agree with all of the above. Be nice to avoid breaking off the bolt, but heating and cooling makes it brittle, unfortunately -- so just have to be careful with it, and hope for the best. One other thing. I often use a box wrench and repeatedly tap it lightly both ways with a small hammer. Corrosion is most likely in the threads, as described above, but can be anywhere incl the unthreaded part of the head. It doesn't seem to take a whole lot of corrosion to stick a bolt. If ya got a saltwater motor there, it just kind of goes with the territory.