removing tight bolts

[js5278]

I need to remove the water cover on my 1984 40HP <br />Evinrude Electric so I can change my thermostat.<br />A couple of the bolts near the bottom of the block<br />seem like they're going to take some effort to remove.<br />They're hard to reach, so I can't tap them with a hammer. <br />I've sprayed WD40 on them in hopes that will help.<br />Any other suggestions? I think I can reach them with a propane<br />torch, but I consider that a last resort. Would I be<br />better off running the motor to warm things up before trying to remove these?

 

[jim dozier]

Re: removing tight bolts

There are many good posts on this subject here, do a search. If the bolt is stuck the torch is not a last option but the first choice. Use care not to heat plastic and heat sensitive parts. If the bolt is difficult to get to with heat and especially if you won't be able to get a drill on it if it snapps off you need to weigh the necessity of removing it against what will have to be removed (like a powerhead)to extract the stub if it breaks and they often will.

 

[js5278]

Re: removing tight bolts

Thanks. I'll apply heat first. If I remember correctly, I need to heat the area around the bolt, and get it pretty hot so that it expands more than the bolt. Is that the correct technique?<br /><br />I've got a stuck thermostat. No choice but to get the water cover off. I'm real nervous about snapping something.

 

[jim dozier]

Re: removing tight bolts

Actually most people heat the bolt. What you're trying to do is expand things and then contract (cool) it is the change that loosens things up. The aluminum conducts heat so well that you will find it difficult to heat it up much anyway. The bolt should get red hot if possible. Patience is a virtue here. Multiple heating, patience, tapping on the bolt, and PB Blaster or other penetrating oil and more heating. I have a Suzuki that I had to remove the thermostat cover on an despite all the above I broke a 6mm (about 1/4 inch) bolt off. That sucker would not come out and I ended up breaking an ez-out off in it and had to drill it out and put in a heli-coil. This story and many others with good advise are here on the board. Do a search. Good luck. There is nothing that can't be fixed if you throw enough money at it. This too will pass.

 

[FlyBoyMark]

Re: removing tight bolts

Heat the head of the bolt to the point of melting and then spray continuesly till cool with WD-40 or similar facsimily.(makes a lot of smoke AND DO NOT INHALE!) You need oxy/acetylene to do this. Shield the surrounding componenets with asbestos shingle or scraps of any kind of sheet metal. Use the smallest possible size torch tip to achieve this. As your doing this tap the center of the bolt with center punch with some omph. The continues spray of lubricant is sucked into the joint via cooling. You may have to repeat this proccess 4 to 5 times. If the bolt does break...IF THE BOLT BREAKS, heliarc drops of steel or stainless to stud to build up to the point where you can tack weld a nut on the build up. Spraying lubricant between build up also helps. This also helps temper to some degree..Heating the aluminum case is a last resort and should be done by highly skilled individuals to avoid serious damage. Usually at this point when you heat the case or casting the bolt WILL come loose but usually strips the casting and a heli coil is required. I have done this to marine and aircraft engine parts for years with about 99% success. I understand this may sound tedius and time consuming, but short of taking the dissassembled engine to a machine shop this works well.

 

[js5278]

Re: removing tight bolts

I really appreciate the help. So after heating the bolt, I should make sure it is cooled back to near room temperature before trying to turn it. Correct?

 

[jim dozier]

Re: removing tight bolts

yes

 

[Doogen]

Re: removing tight bolts

I just went through this with my 1983 35 hp LS electric. i ended up snapping the middle 3 bolts on the water cover. no big deal though heres how you fix it. first get the water cover off. once you do that you will have enough bolt to get a vice grip on and with some liquid wrench they will come out. If you snap the bottom one the safest bet will be to pull the head cover. these bolts should come out easy and its going to cost you $20 for a head gasket but thats cheaper than paying a machine shop $30 - $50 to extract a busted bolt. While the cover is off you can check your cyclinders and de-carb the pistons so its not all bad. None of this was hard with the service manual but its all scary the first time you do it.

 

[js5278]

Re: removing tight bolts

Thanks again jimd.<br /><br />And my lunch went down easier after reading Doogan's experience. At least I know there are reasonable options if something snaps.<br /><br />Now if I could just understand why they make something as problematic as a thermostat so difficult to get at on these motors...

 

[jim dozier]

Re: removing tight bolts

The dark side is everywhere, use the FORCE young Skywalker, use the FORCE (and a blowtorch).

 

[Walker]

Re: removing tight bolts

I would never use an oxy-acetalene torch to heat a stuck bolt on an outboard. Aluminum will give no indications of reaching its melting point. It will just collapse when it gets hot enough and then you're screwed. A hand held propane torch is perfect for this job. Map gas is even too hot.

 

[FlyBoyMark]

Re: removing tight bolts

Walker...<br />"Heating the aluminum case is a last resort and should be done by highly skilled individuals to avoid serious damage."<br />In addition that will not happen unless you're real klutz and you don't follow my instructions. Any other type of torch will usally never get the bolt hot enough to draw in the lubricant. This is standard procedure for removal of seized bolts in the trade next to clamping in bridgeport and boring...

 

[js5278]

Re: removing tight bolts

I only have a propane torch. I'll heat the bolt, let it cool while spraying WD40 on it, then apply reasonable pressure to try to turn it. If it doesn't go, I'll repeat the procedure.

 

[FlyBoyMark]

Re: removing tight bolts

Give it a try..ya got nuttn' ta lose...

 

[FlyBoyMark]

Re: removing tight bolts

As an added note...steel shrinks to a smaller size when heated orange or red, aluminum expands but returns to normal size. Aluminum will not shrink like steel from heat...another reason to heat orange or red on the bolt. By heating the bolt you expand the hole then the bolt shrinks to a smaller size. Acetylene torch has the capability to concentrate the heat on the bolt, other torches have a broad flame and will heat the wrong parts

 

[Walker]

Re: removing tight bolts

Steel does not shrink when heated, it expands. The action that breaks the bond between a steel bolt and an aluminum block is the different expansion rates of the 2 metals. It makes the touching surfaces slip against each other.

 

[FlyBoyMark]

Re: removing tight bolts

Walker..yes it does expand...then it shrinks smaller than before. I've operated my precision specialty marine and aircraft fabricating business for over 25 years now using these methods.....Would you like a demonstration? What your doing is dislodging the aluminum salts that are binding the bolt. Your NOT supposed to remove the bolt when all the parts are hot....That DEFINITELY strips the aluminum threads...

 

[Walker]

Re: removing tight bolts

Okay, we're on the same page.

 

[bonitoman]

Re: removing tight bolts

I heat around the bolts not on the bolt itself. The aluminum around the bolt expands and you can feel with a wrench if the powerhead bolts are going to loosen up. If I heated the head the bolt would expand. If something has been used in salt water, I don't care what you spray p.b. ,w.d.40 or anything that does not penetrate into the threads where it is corroded. I have pulled many powereheads and heat around the bolt and yes sometimes they will snap but the trick is to take it SLOW! Good Luck

 

[LostViking]

Re: removing tight bolts

I agree with walker and flyboy they both have good points, but in my experience as an auto mechanic, I would have to say oxy acetelene would be over kill in this situation, propane would be a wiser choice, The key is as mentioned, patience.... and I second the fact that what breaks the bond is the different expansion/contraction rates of the two metals, <br />One little accident with oxy acetelene and youll be buying a case.