How screwed am I???

[Cecilsan]

So I've been redoing the top end gaskets on my XB9SL as I'm taking a long trip here shortly and wanted to correct a leak I had.

I'm using the Cometic Top End Gasket set and everything buttoned up fine until tonight when I went to put on the headers. I have the full Micron exhaust and when I was putting on the rear header (using the included Cometic exhaust gaskets) I ended up bending the rear exhaust flange. Now the flange won't come back off the exhaust studs.

I have another XB with the stock headers and comparing the flanges, my Micron flange stuck out a lot more when I had it torqued down (which is why I bent it as I was continuing to wrench on it). Is this because I should be using a different gasket or because of something I did?


What are my options for getting the header back off or getting it put on correctly?

Thanks

 

[ToneTheMoan]

Can you post some pics of it to help? Just relax for a while and wait for suggestions because you dont want to break a stud and it appears you have been really lucky not to have done that yet! i feel for you mate and wish you luck with it!

 

[Cooter]

I paid would help immensely. If the flange is simply stuck on the studs because its bent, your only solution is to carefully pry it off evenly. This will take a much smaller meat handed approach than what bent it in the first place!

Pay attention to what you are prying against, and the direction too! You are risking breaking the stud (a terrible replacement job) or breaking an engine fin.

 

[rchuff]

You might have to cut the flange with a Dremel with a cutting wheel so you don't bugger up the threads. Just remove shock and fan so you can get in there. I'm sure you can buy a new flange somewhere.

 

[Cecilsan]

So here it is just sitting in the port. I can't fully see the top part of the flange but from what I can see, its bent as much as the lower one (most visible in the pic)



Here it is tightened up. I worry about the gap between the flange and the head. On my other XB with stock headers, the gap is much smaller. I haven't put the front headers on to compare the gap but it may be possible that this is just how the Micron headers are (I didn't look at the gap prior to taking them off)



Also, the flange on Micron headers does not have a retaining ring that comes off so even if I cut it off, how would I get another back on?

 

[Cooter]

Don't cut off the flange, don't crank on it anymore.

The flange is NOT meant to be flush with the head. You'll be ok with the bent flanges if you leave it alone.

 

[rchuff]

Till he has to replace the gasket then he will have to do something? Better off fixing now then later. He will have to get it off sometime.

 

[Cecilsan]

Don't cut off the flange, don't crank on it anymore.

The flange is NOT meant to be flush with the head. You'll be ok with the bent flanges if you leave it alone.

I know that its not supposed to be flush, but I worry at the distance it currently is overall. My other XB's flange is closer to the head than this one. I don't know if thats an issue with the way the Micron pipe is made (its header is longer) or if its messed up. My worry is that IF its messed up, I'll shear a stud.

 

[ToneTheMoan]

It looks to me like the flanges come off in this pic? they must do surely?

 

[Chicknstripn]

Just torque it to the factory recommended torque spec and be done with it.
Check your service manual for the factory torque spec.

Fire the bike up. Are there any exhaust leaks? If not then leave it be.
I don't think a slightly bent flange is going to cause any type of catastrophic failure.
Just don't over torque it and bust an exhaust flange.

I've had the headers on my bike off and on about a half a dozen times. I've used factory and cometic gaskets. Every time the headers seem to seat differently. I don't think they have ever "looked" exactly the same before or after. I torque the nuts to the recommended spec. I've had zero issues.

If you really feel like you must remove the exhaust, to repair the slightly bent flange or to inspect the gasket, use some sort of puller. Think outside the box. Head to your local AutoParts store let your inner MacGyver loose.
You'll want to use a puller, or whatever you come up with, on the flange while using the stud as the puller center axis.
The key here is that you DO NOT put sudden or abrupt force on the exhaust stud or flange. Take your time. Go slow. Use some lube. Play some slow jams and have a REAL good time with that flange.

Good luck

 

[mrlogix]

what is all that 'shiny' flakes on the crankcase at the bottom of the photo? You wrenching on it that hard? Looking at the surface rust of the studs (and threads), I wouldn't be cranking on them two much. Just my .02. If it's not from you wrenching on it, rotate the engine and see what it is. Plenty of vids out there to show you how and plenty of help here on the forum.

 

[mrlogix]

what is all that 'shiny' flakes on the crankcase at the bottom of the photo? You wrenching on it that hard? Looking at the surface rust of the studs (and threads), I wouldn't be cranking on them two much. Just my .02

 

[Cecilsan]

It looks to me like the flanges come off in this pic? they must do surely? View attachment 4021

Micron headers are a 4 piece system. Each pipe comes apart in the middle'ish but the flanges at the exhaust port don't (at least mine) have retaining rings.

I appreciate the replies. I guess I'll torque it down and run it as is. I'm less concerned with getting the exhaust off at a later date than I am breaking a stud.

 

[Cecilsan]

what is all that 'shiny' flakes on the crankcase at the bottom of the photo? You wrenching on it that hard? Looking at the surface rust of the studs (and threads), I wouldn't be cranking on them two much. Just my .02. If it's not from you wrenching on it, rotate the engine and see what it is. Plenty of vids out there to show you how and plenty of help here on the forum.

Those aren't from the studs or flange, its from the gasket in the exhaust port. I'm with you on the surface rust, which is why I bought new nuts

The frame is off the engine at the moment

 

[ToneTheMoan]

I would be tempted to try what rchuff suggested and cut it off with a dremel if you can get in there cut between the stud and the header because it looks like there is room for a weld on the flange there without affecting anything else and a weld wouldnt weaken in but just weld it straight! lol

 

[Mope]

Couldn't believe there was no way to get the flange off so I did some looking. From the old days when Micron's were being made and ASB carried them:


You don't need the retaining clip. the flanges are captive on a Micron.

But you should tighten it correctly with new SE gaskets in it. Stock gaskets only work well with a micron if you radius the tips. 7-9 ft lbs, each time after the first 5 heat cycles, on the three you can get to. Do the one you can't a little higher than that on the first tighten since you won't be able to get to it again once you rotate the engine up.

We recommend mounting the Micron using the Screaming eagle type flat gaskets (which we have on the site) instead of the stock tapered style ones, as the SE gaskets don't squish out into the ports as much. They sometimes don't seal as well as the stock type, but I've never really had problems with them.

All from Al over at ASB.

 

[Chicknstripn]

Great investigative work there mope!
I tell ya, some of you guys don't get enough credit for all the leg work you do to help out fellow Buellers.
Big thumbs up to you Mope and everyone else that goes above and beyond to find those answers that someone else "has search everywhere" for to no avail.

 

[Cooter]

I'm with ya, Chicken. I've searched everywhere?!?! What kind of oil goes in the primary???

 

[Chicknstripn]

I hear canola gives you 10 extra HP.
Totally negates internal mechanical losses.
I saw a YouTube video, so it must be true.

 

[mrlogix]

I hear canola gives you 10 extra HP.

really only 5, you have to mix it with 2 stroke oil at 600:1 for the other 5.