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Discussion Starter #1
I am in the process of rehab on my 95 TW200 project. This bike has been neglected, crudely maintained, and apparently stored outdoors most of its 25 year life. I am doing a bobber hollow mod rat bike build. The exhaust is very rusty and needs replacing. I have hit a snag on getting the exhaust header bolts out. The engine is still in the frame. The socket head bolts are very rusty. The left side bolt wrench socket is rounded out. The right bolt is accessible with vice-grips but does not move. I am trying to avoid breaking the bolts off in the head. Any suggestions?

I am thinking of drilling the bolt heads off to allow removal of the pipe and flange. This will allow better access to the bolts where they enter the head. Then soaking them with Kroil or PB Blaster. If that does not work the only other idea I have is to bring out the torch and heat it up.

Any words of caution or helpful hints are appreciated.
Terry
 

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Sounds like you need a tap reverser – you drill a small hole down the center of the jammed bolt, then crank a tap into it that has an anti-clockwise thread

At some point, the reverse threaded tap will bite, and hopefully the jammed bolt will start to come out

You can apply heat or anti freeze oil at any stage during the process

If you end up ballsing the whole thing up, there’s always helicoil …..
 

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Weld a nut onto the bolt head. Heat will help loosen the threads and give you a new place for a socket. Don't drill them off till you try this. This one trick has saved my bacon many times.
 

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Discussion Starter #4
Thanks guys!
Welding a nut on sounds like a good plan. I like the fact that it adds heat right where its needed.
Drilling for an ezy-out tap does not seem real easy in this small bolt to me.
 

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Ezy Outs are great until they snap.

Then you have a jagged surface that is as hard as glass to address

Treat them with respect and bottle out before it snaps!

However, I have a replacement exhaust to fit to my 125 so forewarned is forearmed - thanks!
 

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Discussion Starter #6
You are correct Tris. EzyOuts will snap. Been there Done that!
 

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I had this same issue with a 1988 I rescued. I cut a straight slot into the stripped socket head with a dremel cutting wheel so a flat blade attached to my impact driver fit tight. Then I heated the area and gave a few slaps with a heavy hammer and the hand held impact driver. The bolt broke loose and all was fine. I will suggest when you put it back together that you buy the OEM bolts from Yamaha as I do believe they are probably grade 8 and intended for high heat areas. I also suggest the use of a high heat thread lubricant. These hex head bolts tend to round out quite easily and more so if your hex wrench has a little wear. I bought a set of ratchet hex drivers and use my slap hammer impact tool religiously and always before I try too hard without it.

GaryL
 

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My suggestion (once you get them out) is to chase the holes with a tap, to clean the threads out....then install studs instead of using bolts.
Some people just cut a chunk of "reddi-rod" others use long Allen set-screws, others use actual exhaust studs.

This idea works on the valve covers as well...it's more forgiving to (accidentally) over-torque a nut on a stud, as opposed to stripping the holes in the head!
 

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Discussion Starter #9
Studs are a great idea if I ever get the bolts out! I would definitely go that route. Tried heat today. No joy. Soaking with acetone/ATF 50-50 mix now. I really do not want to destroy the bolts. I may just wrap the pipe and live with it as is. I have a SS 225 pipe that I wanted to put on.
Terry
 

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Sometimes, it takes several cycles of heat, cold and penetrating fluid...good on you for trying the ATF. It will happen, the trick is NOT to get too frustrated with it and do something rash.
I've heard of guys that did this for three days until finally, on the 3rd day...it broke free.
When it comes to heat, you have to judge how much is enough and when it's too much. I tried doing some aluminum brazing with special rods, but I wasn't able to generate enough heat with a hand hand-held propane torch.
Maybe use one of them REAL CAREFULLY!!!
When the aluminum all around the bolt is hot, give the end of the bolt a few sharp taps with a ball-peen hammer. The percussion breaks the bond between the two metals and sometimes is enough to get the job done.

As I recall, the Allen bolts on this model have a tensile strength somewhere between eraser and glass....I sheared one off in the armature casing with very little effort.
Those in the exhaust port can get annealed by the continuous heating and cooling cycles...add a bit of rust and/or electrolysis and you have the makings of an "Oh $hit!" moment.
Once you get the old ones out, whatever method you choose, make sure that you exercise the fasteners at least once a year (with anti-seize) to keep them un-bonded.
 

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I'll also go with the stud idea use high tensile (with thread locking compound), and look for brass exhaust nuts, they usually are either crimped on the one side or slotted and bent down to "bite". Copper is not affected by heat/cold cycles as much as steel.

ATF will work wonders, see if you can find "Wurt Rost Off" either the "Ice" or "Plus". We used that at the exhaust shop I worked at, it's a bit on the expensive side, but it does work.
 

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Any penetrating oil that smells like Wintergreen generally works well, as it has methyl salicylate in it, which works very well on rusty studs. Or as you are mixing your own, go the a pharmacy and buy some and add to the mix. It really does work.

I'm also keen on the slotted head and impact driver method. Used it many times successfully. As you have time, gentle tapping with a hammer periodically while long term soaking works very well.

Heat works well too. Sometimes I think the heat from welding on a nut does as much as the nut.

I own many easy outs, but I've broken several times the amount I own...
 

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Discussion Starter #13
Thanks for all of these great suggestions. Keep them coming. I have not given up.

It would be a lot easier to access the bolts if the motor was out of the frame. The frame member in front of the engine is really in the way. But I don’t think I can drop the motor out with the pipe still on it. Catch 22. I am struggling with the idea of cutting the pipe off so can drop the motor and gain the best access to the bolts. This gives me the best chance of getting them out.... and also of breaking them off. ��. BTW I have the same issue with one of the carb spigot bolts.

I have lost my hammer impact tool and have a new one on order. Maybe I will have bit the bullet and cut the pipe off and out of the way by the time the impact hammer gets here.

Terry
 
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