Airhead Exhaust Wrench

Discussion in 'Airheads' started by SUVslayer, Jan 6, 2010.

  1. bpeckm

    bpeckm Grin!

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    .... 'cept "in theory" you want the nuts to get hot faster, and expand more, than the threads.....



    .... but then, nobody ever accused reality of knowing about theory.....


    ... :wings
    #21
  2. SUVslayer

    SUVslayer Long timer

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    It's been a little hard to set time aside to work on this, but I'm finally getting into the meat of the matter.

    I managed to borrow an exhaust wrench (thanks Mykill!!) but was unable to loosen the nuts. So I bit the bullet and cut them. I was lucky to find a replacement set in Long Beach for a mere $10 each, which seemed a DEAL.

    I used a dremel, some files and a screw driver to get them off. And I didn't destroy the threads, despite my heavy handedness!

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    The offending matter that started all this:

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    Definitely time to clean things. This is the inside of the heads:

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    The dangly semi-snot is I think the old seal. Don't think it was doing much.

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    The push rod seals looked ok, but were rock hard.

    So now I've got to clean things up. I've read a wire brush, and even a wire tip for the dremel will work. I'm just concerned about scratching things. Is brass better than steel? Any suggestions? Also, I generally use kerosene to clean things. Is this a reasonable solvant to clean the heads and cylinders, or should I use something else?

    Another crummy SoCal sunset

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    #22
  3. mark1305

    mark1305 Old Enough To Know Better

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    When the carbon has been loose and flaky, I've used the rounded end of one of those double-wide hacksaw blades to gently scrape off most of it. Then finish with a wire cup brush or a 3M abrasive wheel (the black sponge looking thingy). Trick is not to scratch anything.

    Hardened deposts I've just gone straight to the cup brush or wire wheel and patiently polished it out. Be very careful to stay away from gasket or o-ring surfaces.

    I've never decarboned a piston in the cylinder so as to avoid pushing carbon down between piston and cylinder wall. That's just me, though.
    #23
  4. SUVslayer

    SUVslayer Long timer

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    Thanks Mark. I'll look into those.

    Cylinders are off, so no cleaning pistons in the bores. I did notice while cleaning out the holes in the case where the push rod seals go some clear, stretchy O's... I would guess it was sealant, except they were such perfect bands (think thin, clear, circular rubber bands). I'll take some picks and post. Is there anything that goes on the push rod seals that would do this??
    #24
  5. SUVslayer

    SUVslayer Long timer

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    Looking at the seals themselves, there are ridges on the part that goes into the case - that's what probably created the "rubber bands." What kind of sealant is used here?
    #25
  6. mark1305

    mark1305 Old Enough To Know Better

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    I've read of some folks using a small bit of RTV on new pushrod seals, and read from others not to. I haven't had to do that job yet on my ST - still only weeping enough to wipe off the oil film after every few rides. :D
    #26
  7. danedg

    danedg Horizontally Opposed

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    They really don't look that awful....you REALLY don't want to scratch or gouge 'em in any way...new gaskets and seals and button her back up...
    #27
  8. KhaoSanMan

    KhaoSanMan Airhead

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    After talking to my local mechanic, I am left with the question...

    why take off the nuts every year to add anti-seize?

    wouldn't this just add to the number of times that the threads could get boogered?

    why not just wait until you NEED to take them off and deal with cutting them then?

    I guess at 30$ each they are not cheap, and preventative maintenance is a good thing in that sense. I however, have yet to take them off once and therefore am wondering what's the point if I have to take a risk just to prevent exactly what I am risking?
    #28
  9. Airhead Wrangler

    Airhead Wrangler Long timer

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    I guess if they don't come off easily, wait to take them off until you need to. Then once you replace the nuts that you had to cut off, remove and anti-seize them yearly so you never need to cut the new ones off.
    #29
  10. I GS 1

    I GS 1 I 90S I

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    I agree. They do need anti-sieze but I wouldnt take them off unless I had to - you can get a bit of thread breaking away at any stage causing the problem. They are also not always a problem to get off. I recently found that with a heat gun I was able to get a pair off that had been in place for about 30 years (1975 R90S)
    #30
  11. jtwind

    jtwind Wisconsin Airhead

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    Properly maintained threads don't get "boogered" by taking them off and on. Removing the exhaust is standard for lots of airhead maintenance including on some bikes, oil filter changes so just leaving them until you need to cut them off isn't a great idea. Frankly I think You have a greater chance of damaging things by trying to remove siezed nuts and cutting than you do by regularily taking them off, cleaning them and applying fresh anti sieze.
    #31
  12. mark1305

    mark1305 Old Enough To Know Better

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    Big +1.
    #32
  13. caponerd

    caponerd Kickstart Enthusiast

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    Yep. Mine come off for every other oil change (when I do the filter), and I've been doing that for 10 years now.
    You just have to be careful to avoid over tightening when dealing with aluminum threaded parts. They don't wear out by themselves.
    #33
  14. I GS 1

    I GS 1 I 90S I

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    I must say that I would caution people against taking that as a general rule. While I would agree that “properly maintained” threads usually don’t get “boogered”, they still can and some do. Of course you have to take them off on some models for some maintenance items, but the question is what to do if you don’t. It is a high heat application and the anti-sieze has to stand up to this. Not much thread area needs to “weld/oxidise” together to cause it to be pulled away and cause a major problem when you unscrew it. (I agree that with a well used nut, there is less chance of a bit of manufacturing scwarf being around/loose to cause the problem and that anti-seize is pretty essential on a new nut for this reason – but the “weld” problem can occur in a relatively short space of time.) The other things we need to think about are that in some applications it is recommended that you only use a nut or bolt once to maintain it’s strength properties – generally tightening and loosening is not good for nuts and bolts (eg. I would say don’t ever re-use a spoke unless it’s only to get you home), and that with the type of tool most of us use for airhead exhaust flange nuts we don’t accurately measure torque each time we tighten them up so each time we subject the molecular structure to a different effect. IMHO for what it’s worth
    #34
  15. Wirespokes

    Wirespokes Beemerholics Anonymous

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    I think you're over-analyzing this. Truth of the matter is that having the threads clean and slippery, with anti-seize applied, they don't have problems.

    Hey, you've got to remember who designed these things - GERMANS! They were meant to last! :wink: If anyone can engineer something, it's them. (don't pay any attention to those self retracting side stands...) And they were meant to be re-used... often.

    Anyway, it's born out in practice, that clean, anti seized exh nuts don't weld on. And definitely don't over-torque them! Torque only enough to stop any leaks. I've seen them so tight that the clamp ring left a squished band around the header. :eek1

    Once that happens, no amount of torque will stop them leaking. One of the manuals calls for an ungodly amount of torque on those things (as if you could measure the torque anyway), but it should only take a few light raps on the wrench with a rubber mallet once it's hand tight.
    #35
  16. Martian

    Martian Long timer

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    Hell, I loosen both of mine at each oil change and apply high-temp anti-sieze before retightening them. I use HPMGuy's beautiful wrench with a 6" long 3/8" extension stuck in it and just snug it up. I never had them leak or gall or sieze or exhibit any other negative behavior.

    Tom
    #36
  17. SUVslayer

    SUVslayer Long timer

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    Quick update, since not a lot's happened:
    Took the pistons off, since I've decided to get the juggies beadblasted. I know I'd regret it if I didn't get all the gunk and carbon off before reassembly. Now I'm waiting for new rings, since why not? let's do rings too - although, I have to say the one's I've got look pretty good. I don't think this motor's been apart before, but everything looks pretty good, including valve seats.

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    Anyway, took some scotch brite to the headers since I was bored and they looked pretty chunky.

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    And now I'm looking at the carbies and feeling real guilty for neglecting them too...

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    C'est la vive. Another minor job becoming... not so minor.
    #37
  18. Wirespokes

    Wirespokes Beemerholics Anonymous

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    I wouldn't replace the rings either - they can be a pain to seat sometimes. And besides, they tend to last a 100,000 miles anyway. So why bother? They're just way too easy to replace when it's time.

    Get some spray carb cleaner. Put them over a pan and spray a little bit, then what drips into the pan, grab with a tooth brush and scrub. It won't take long to have them sparkling. Carbs clean up pretty quick. And if the bike was running fine, don't worry about rebuilding them. Leave em be, just clean them.
    #38
  19. Jasper ST4

    Jasper ST4 Guest

    I have a wrench branded "New Age", made in Canada. I bought it at least 20 years ago and have no idea where I got it, probably some rally info. I bought one at the Beemer shop last summer and took it back, it left marks on my new purty exhaust nuts! The Canadian item is aluminum and never left a mark so I'll stick with it, I don't know if they still make them.

    Absolutely, make loosening and redoing anti-seize part of the regular maintenance. I do it annually now, I lost some threads once and almost lost a set the last time I took the pipes off, but I prayed, cursed and finagled them off successfully. They had high temp anti-seize on them but years of riding takes its' toll.
    #39
  20. SUVslayer

    SUVslayer Long timer

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    So, another update, at long last. Guess I'm hyjacking my own thread here.
    Ended up getting the heads, cylinders and pistons bead blasted at Angel City Cycle. They came back so clean, they make the rest of the bike look filthy and scummy. I've spent as much time wiping old caked grease and oil off as I have actually fixing things.

    As part of that, JR installed new rings for me. Getting the cylinders over them turned out to be a bigger booger than I anticipated, since I didn't have a ring compresser.

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    It took quite a few tries, some sore fingers and plenty of cheap Costco beer to get the damn things on, but finally I got my technique down and they slid home. I almost (almost!) wished I had more cylinders to hone my skilz, but screw that. Two's enough.

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    Cheap costco beer.

    Then it was time for the heads and rocker arms. That should have been easy, except one of the rocker arms had a bad bearing. I bought new bearings, figuring I could just slide the old one out since there was no lip or anything. WRONG. More blood, sweat and tears trying to get the darn thing out. Finally, I came up with a home made bearing pull to squeeze them out:

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    Basically, a long bolt, coupla big washers and a 14mm socket which was tailer made to slide into the rocker arm and push the needle bearings out.

    Once I got those out and new ones installed (I submitted and took it to a shop to press the bearings in) it was short work to install them and adjust the valves.

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    Then the valve covers and carbs and it started looking like a bike again.

    More Costco beer:

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    Meanwhile, while I was waiting for bead blasting and such, I monkeyed with the neutral switch to fix its leaking. And broke it.

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    dumb dumb dumb

    Another day down, had to get a new switch. Cleaned all the gunk from under the tranny and installed the new switch.

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    You might be wondering what all that orange stuff is. Well, it's high temp gasket sealer, added in extreme quantities. I'd replaced my oil pan gasket and somehow thought I needed more of the orange stuff than I did. That had to come off and be redone. This poor dumb bike, I'm really cutting my teeth on it.

    Finally, assembled the exhaust, oil cooler, and crash bars, and suddenly - wow! it was pretty much all done.

    Screwing on a replacement to an original offender, with anti-seize:

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    I also cleaned up the airbox and disconnected the plumbing that routes the crank case effluent into the carbs. A little absorbing material was fitted to the bottom of the box to collect any oil that drips out. Thoughts on this? It was a suggested mod, to help minimize carbon buildup in the cylinders.

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    Finally, today I took it out for a spin. One side seems louder than the other, I think I need to check valve clearances, but otherwise, it seems to run pretty good. I'm baby-stepping it around while things settle in, but I'm just amazed it didn't blow up on me.

    After the maiden voyage:

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    Best part of all - the pushrod tube seals don't seem to be leaking! This blew me away.

    Of course, all this took about 8 times longer than it should have. But now the bike's starting to come together. In recent months I've had the drive shaft rebuilt (well, that was a while ago), replaced final drive bearings, new top end, new steering head bearings, new throttle cables, cleaned the carbs, and had the Ohlins rear shock rebuit. I need to slap new brake shoes on, which I'll do in the next week or so. Good to go for the dual sport ride in Death Valley end of March!
    #40