Need expert advice for welded exhaust studs, 250ES

[King Trikester]

This engine has great compression and shifts through all the gears, it came in a 1985 trx 250, I was going to transplant it into a big red that I have, when I bought it I did not realized that the exhaust was welded to the head, what would you do or what can I do to fix this.



As you can see there is not much to work with. Do these studs come out? If so how would you do it? I have failed on removing them and it appears that they might be cast into head. Is there a fix for this. Who ever Owned this was trigger happy with a welder, everything you can think of has been welded and more,
The engine runs great so I don't want to tear into it if I don't have to. I stripped this trx to the ground and Scraped the frame. It was unsalvageable thanks to the red neck trigger happy wanna be welder.

Any advice is appreciated

[ustin666]

weld a nut on the stud it should come right off. the heat from the weld should free it up.

[trike savior]

agree. weld a nut to what is left of stud. be careful with the heat. the heat will free it up but you can also melt the aluminum with too much heat. it is hard to do but possible, so just be careful. do not let the welding wire hit the aluminum.

[fabiodriven]

Do your best when welding the nuts on, that's not easy to do at all. Once you get the nuts welded on, get yourself some CRC Freeze Off. It's $6 and it will change your life.

[6speedthumper]

And, if all else fails, you can drill them out and re-tap. Had to do that to my 350X head because all the studs were broken.

[fabiodriven]

And, if all else fails, you can drill them out and re-tap. Had to do that to my 350X head because all the studs were broken.

Although not impossible, I'd highly suggest not doing this freehand. It gets ugly quick. You might be better off to pull the head and have a machinist take care of it.

[81Rmachine]

Although not impossible, I'd highly suggest not doing this freehand. It gets ugly quick. You might be better off to pull the head and have a machinist take care of it.

I've seen it all too often drilled out anywhere BUT the actual stud LOL. The drill bit walks off and right in to the soft aluminum.

This is a 200x head I repaired for a friend. Someone had drilled next to the one stud and messed up the original threads and they broke a drill bit off in the other one so I came up with a decent solution thats worked well a few times. I have it mounted in the seat and guide machine with a carbide endmill to machine out the original studs and the high speed steel drill bit. The original hole was damaged so I went to a stepped stud. In fact just about any hardware store carries a bin of "automotive studs" and they have some that are 6mm x 1 on on side and 8mmx1.25 on the other and they work great for this but as fabiodriven said, do your absolute best and get the original out if you can. That freezing stuff I've also seen in loctite brand called freeze and release and some other company called numb nuts lol! It works great and its well worth the price, Good Luck!

[tri again]

All great advice.
I shoulda patented the freeze idea. Been using freeze wart remover for years on press in carb jets.
Anyway, I actually got a job by drilling out an exhaust stud in front of a new boss.
Centerpunch it first, no wait, don't drill at all if you can help it.
ok, centerpunch so the bit centers, LEFT handed drill bits so in case they bite, the are more likely to spin out the bolt instead of breaking off.
ASSUME ez outs will break and they are hardened and cannot be drilled unless done by superman or wonderwoman.

I enjoy boiling penetrant with a torch but as stated, just don't make it worse.

If you want to get crosseyed, try the search key for something like 'broken exhaust studs'.

I've also heard that stainless may be a better way to go but I just don't trust metals and interactions so make sure first...as with using anti seize too.

I also grabbed some 8 by 1.25 thread pitch but an 8 by 1.00 got mixed into the adjacent bin and Almost wasted my whole project.

[fabiodriven]

I second the left hand drill bits IF you have to drill. EZ outs are a waste of time and money and will cause nothing but more problems. If you ever break off an EZ out or drill bit and can't get them out, shatter them with a punch and take them out in pieces. A lot of people don't think to do that.

[tri again]

Thanks fab.
another thought, if yer scared to weld, you can get a large diameter 'fender washer'
as sort of a background shield to separate the stud to be welded from the head.
Like 2 inch diameter with a 6mm small hole. I'm sure you've seen them and pretty sure they've been called fender washers, maybe something else too.
That way you can use a slightly larger nut and more room to drop a bead in there.

Decreases the intimidation a little.

[fabiodriven]

another thought, if yer scared to weld, you can get a large diameter 'fender washer'
as sort of a background shield to separate the stud to be welded from the head.

You learn something every day. I did manifolds for two years straight and never thought to do that. I just did a manifold on a 3406 CAT about a month ago and might have tried this.

[6speedthumper]

Although not impossible, I'd highly suggest not doing this freehand. It gets ugly quick. You might be better off to pull the head and have a machinist take care of it.

I'm a mechanic. Have all the tools at my disposal to do it right. Although, my drill press is busted, and I have to do it free hand at the moment. I always center punch and use a smaller drill bit to drill a pilot hole, then step it up. Left hand drill bits are the cat's nuts. But, I'm used to doing it free hand after the dozens upon dozens of broken exhaust studs on GM 5.3/6.0L, and especially the Ford 5.4L. When it's in the vehicle you have no choice other then removing the head. Which can easily be avoided if you're not and idiot, lol.

[atc007]

You don't have to be an idiot to screw these up freehand !! You are just that damned good! As to the op's question. I don't think there's enough meat on yours to get the nut welded on. Worth a try for sure,it will be the heat from the welding and the cold from the freezing that will bring them out. Also,,I should KNOW this,but I think the TRX 250 doesn't just drop into a 3 wheeler. Output shaft length?? Check it all out on here before you get in too deep. Good luck!

[King Trikester]

ok, thank you all for the advice, I am going to bring it to the shop at work on friday and give it a shot, there are a couple experienced welders here but i would like to try it myself. As for the engine not being a direct fit im ok with that, I have another trx that also needs an engine and i was planning on rebuilding the one in the big red, all i can tell it needs without tearing into it is the one way bearing.

to be clear, weld it, the heat should "loosen it up", then freeze it and out it should come? sounds like a fun challenge I will take a couple more pics a long the way and let you guys know how i make out. Thank you again.

[King Trikester]

also from what I understand changing the output shaft isnt that hard? that is probably what I will do