Broken Exhaust Manifold Post

[TiminIndy]

I while back, I broke off the post that comes down off the exhaust manifold. Damn nut wouldn't come off and I tried to give it just a little more and it snapped! This is the post on the forward side that you attach a nut to to hold the exhaust on, then there is bolt that goes into the corresponding hole on the aft side of the manifold. I've been able to keep the stock exhaust on there with just the one bolt, but I don't know how long that will hold. I'm not comfortable putting my Leo S on there with one bolt, as they way the two parts fit together it really needs to be held on both sides.

I've been hearing and feeling a little leakage there (loss of power, like compression is low), and my gasket was a little torn up, so I just put in a new one and snugged everything up real good- we'll see in a minute if that makes a difference.

My question is: What's the easiest way to try to replace this post, which I assume the original is a part of the manifold itself?

I was at a shop a few weeks ago having a tire mounted and the guy acted like he could do it, but figured he'd have to drop the whole engine out and he isn't familiar with the Ditech at all as far as unhooking the electronics, etc... We do have an Aprilia dealer here, but they have shown that they aren't all that familiar with the Ditech either, and I'd rather not deal with these guys if I don't have to. I don't know if the guy intended to weld a new post on or tap out a hole that you could put another bolt in. It's certainly hard to get to, so imagine there's no way to fix it without a lot of disassembly.

I mentioned that there's a pictorial thread showing the whole thing come apart that he could use (Scootnfast's cylinder replacement thread), but I don't have the time, tools, or inclination to try to do this). Even if you get it apart to this point, it would till be difficult to get to:



Maybe the way to go is get it up on a stand and just remove the center stand assembly and put some heat guards in for the welding. Any ideas?

With nearly 12,000 miles, I think if I had it all the way apart, it would be stupid not to rebuild the whole thing.

[pehayes]

The exhaust won't hold long with only one bolt. You MAY be able to salvage this in place if you're careful. You need to buy a 'stud extractor socket' that looks like this:

http://www.thetoolwarehouse.net/shop/SKF-287B10.html


or like this:


Make sure you move carefully in each direction to see if the stud can be loosened from the casting.

If it breaks off again, flush, then you'll have to remove the head and have a machinist carefully drill and re-tap for a new stud.

Patrick

[SilverSurfer]

Did it snap off right even with the port, or do you have any amount of shaft left to grab ahold of? I don't know if it is, but I'm hoping for you that it's a removable threaded shaft, that you could replace if you just get the other one out. If not... the block is iron, I don't think you could weld on another stud (shaft), so drilling and tapping would be the only possibility I'd think. I'm not sure how much all that would cost for someone.... but if you're willing to do the work yourself, you could just buy a new cylinder, and that would work for sure (obviously).

[TiminIndy]

There's about a half a centimeter sticking out--not enough to get a nut on.


Is that post threaded in there, or is it permanently attached?

[jwtoe]

It is just a stud into a threaded hole in the cylinder. Put some penatrating oil on the broken stud overnight, apply heat and use a vice grip to remove it. Not a big job just awkward in the frame. Your dealer may be right that the best way is to remove the engine. This is not a big deal either. I just removed mine in less than an hour.

[THE MAX]

There's about a half a centimeter sticking out--not enough to get a nut on.

half a centimeter is MORE then enough to put a nut on and weld it INSIDE the left over tread