Bolts ?

[RTZ]

Hello fellow boaters, I have been doing some maintenance on my 1987 88hp Evinrude engine. I am by no means a mechanic, but know enough to do some maintenance items. My questions are about bolts. I have owned this engine for about 20 years and only run in freshwater, but the previous owner obviously ran in salt due to corrosion I have found. I had trouble getting some bolts out on the head covers and broke a few. They came out with heat, hammering, and prayers. First question, How do I get other bolts like head bolts out without breaking? 2nd question, before I re-install I have been tapping to clean out holes and cleaning bolt threads. I have been reinstalling using OMC triple guard marine grease on the bolts in hopes of easier removal next time. I notice others use oil, gasket sealer, blue locktite, etc. to lube up bolt threads and minimize corrosion. Is what I am using going to be fine? Thank You any any insight.

 

[F_R]

The grease will work as well as anything.

 

[JimS123]

Lube the bolts with penetrating oil for awhile so they get some penetration (hopefully). Mask the head to insulate it, then put dry ice on the bolt head. Sometimes it works, sometimes not.

I personally use Blue Locktite when I hope to never have to remove the bolt again, and anti-seize if I know that removal is probable.

 

[halsteadmorris]

Warming the engine up would help. Heat helps expand the metals and loosen things up a bit. Other than that, WD40 is your best friend.

I personally use Blue Locktite when I hope to never have to remove the bolt again, and anti-seize if I know that removal is probable.

This is very good advice ^^

 

[cprodave]

I hear the best heat to apply is "The Blue Wrench" oxy/acetylene torch. Car mechanics adage "if ya can't turn it then burn it". I don't own a Blue Wrench but just yesterday i got a stuck bolt out a lower unit by soaking it with multiple penetrants for about a week (this alone didnt work) then holding a heat gun on the aluminum gearcase adjacent to the stuck bolt. I heated it until lubricants bubbled out, applied more lubricant, etc repeated several times. Interesting that this didn't even burn the paint, but that portion of the housing was hot enough to burn fingers. Be careful to not melt any plastic/composite components...best bet though is to make a friend who has this torch.

 

[Chris1956]

I have had luck with a mapp gas torch. If you heat the bolt and apply a penetrant and let it cool, it can pull the lubricant into the threads. You usually need to repeat the hot-lube-cool cycle several times.

 

[Crosbyman]

you can also try freeze chock a can of keyboard dust cleaner from the dollar store held upside down will shoot liquid propellant to freeze the bolt head

hopefully the contraction can break the bond between the bolt and the engine body

I also found that Dupont silicone spray for snowblower chutes is really thin and liquified enough to sneak in the threads to release everything


patience bring joy....