Rusted Bolts

[soup]

I have an '89 200 VRO that I am attempting to remove the powerhead. I am having trouble with the bolts that attach the powerhead to the exhaust adapter. They are rusted very bad with the heads starting to round. 9/16 and #14 box wrenches both slip when trying to loosen these bolts. I have a special socket that I can use, but I'm afraid that with too much torque, I'll snap the bolts off. <br /><br />Any suggestions?

 

[Joe Reeves]

Re: Rusted Bolts

I have had luck using a hand held propane torch with a blow torch tip to heat the aluminum surrounding the bolt shafts, then pounding a metric socket up over whatever's left of the bolt head. The heat should prevent the bolt from snapping.

 

[KiHoPro]

Re: Rusted Bolts

I had a similar problem with my O/B trying to remove the lower end unit. The main bolt was frozen in place. <br /><br />Being an ex-German car mechanic comes this resounding echo in my hollow head “NEVER USE HEAT ON ALUMMINUM”. Too much heat will do funny things to aluminum. Now I know that sometimes there is no other way. However, I chose other methods to resolve this issue, as in solvents and penetrates. Brut strength, works too, mixed with some finesse.<br /><br />Now I snapped my bolt. Sheered it right off at the case. I had to us a Drill, Tap and Die and installed a Helicoil to re-thread my upper case. <br /><br />There is no easy way to fix this issue, No Quick Fix. You got to do…. What you got to do!<br /><br />Whatever method you use… Best of luck.

 

[Joe Reeves]

Re: Rusted Bolts

KiHo.... Using heat on aluminum is a everyday event pertaining to outboard engines, especially in salt water areas.<br /><br />However, one must never use a acetylene torch as that will absolutely cause the aluminum to melt quite quickly.<br /><br />The hand held propane torch, or even the tank type propane torch assy will never get hot enough to damage the aluminum casting.

 

[piniongear]

Re: Rusted Bolts

I had the bolts on my 140 so rusted in this area that I thought I would never get them out. The three long bolts on the starboard side came out by pounding on a 7/16 impact socket onto the heads which were originally 1/2 inch size.<br /> On the port side these three bolts were rusted so bad that I had to cut off the heads flush with the bottom of the lock washers and then grind them flat until the washer fell off, leaving about 1/16 inch of straight sticking out.<br /> I wound up drilling the rear bolt with a 1/4 inch cobalt bit and trying a #6 EZOUT. No luck, and a #6 is one big tool. I used an acetylene/oxygen torch and a small rosebud tip to heat the aluminum up. Works fine, just be sure to keep the torch moving at all times! <br /> After the leg came off, I could unscrew those three long bolts with my fingers. The corrosion was from the bolt head up about one inch on every bolt. They would never have come out using any kind of tool.

 

[umblecumbuz]

Re: Rusted Bolts

I second all that's been said about heat. <br /><br />As I heat, I always keep putting on lubricant. it smokes like crazy, but it penetrates and keeps the heat from localising too severely. And I do it in stages - few minutes at a time, then let it cool. Repeat.<br /><br />I don't spray the lubricant - too dangerous - always from an old-fashioned oilcan.<br /><br />Ciao

 

[lark2004]

Re: Rusted Bolts

Yep, and time, I lubed, heated, lubed, and heated some more, over several nights, the bolts on the bottom of my block came out eventually.