My First Bike: A broken 1980RT

Discussion in 'Airheads' started by tbg, Jun 5, 2013.

  1. tbg

    tbg Bike Destroyer

    Joined:
    Jun 3, 2013
    Oddometer:
    18
    Location:
    South Dakota
    Howdy folks. Big fan of the forum.

    So I recently bought my first motorcycle, a 1980 R100RT with 110k miles, hoping to get a working project bike I could ride on, and learn some basic mechanics. Unfortunately I got what I wished for.

    After a few weeks of riding, I made a 60-mile jaunt, and the positive battery terminal completely melted off. Turns out, the previous owner had installed a new battery, but used a screw without enough thread, stacked on washers. I’m guessing that the screw was a little loose, and the resulting arcing melted everything apart. After getting a new battery, and a fresh, well fitting screw, the bike started with no problems.

    Excited that the engine was running, I took the cycle for a spin. About a ¼ mile down the road, as I shifted into 3rd, a knocking noise began, and I immediately lost power. After a trailer ride home, the bike made an awful noise upon hitting the starter, and eventually refused to start altogether. Having read a few articles about the $2k o-ring on the oil filter, my friend and I figured we could diagnose the oil and get an idea of how the bike stood. Unfortunately, our work showed a few issues:

    -The starter was fixed by gently touching it. Apparently it was just stuck?
    -The oil we drained was pitch black, presumably having been burned.
    -The right exhaust and muffler are rusted together, requiring us to pull the entire pipe off. (The Clymer manual recommended pouring boiling water on the exhaust nut if stuck, and it worked!)
    -Upon tearing open the old filter, we found small particles of shiny metal, and an inch-long jagged sliver of a light metal-ish composition, which, according to Snowbum’s site, is either off the main bearing from a worn top sprocket and chain (shaft?), or off the cam chain tensioner.

    After ordering a few washers and screws from the nearest dealer (unfortunately 4 hours away) we reattached everything, and got the oil light to turn off. Unfortunately, after opening the fuel lines, the bike made an awful cranking/snapping/clattering noise as I applied throttle, attempting to start the engine. In addition, very noticeable smoke began leaking from the left exhaust. Out of desperation, we put in new spark plugs, and noticed the left plug tip was covered in burnt oil.

    So, we’re pretty sure that there is something very wrong in the left engine head, where the noise and burnt oil seem to be originating: perhaps a hole in the piston or a blown gasket? This is the first mechanical work I’ve ever attempted, and while I’m having a blast and getting by with my buddies know-how and the Internet, we agreed you guys could probably help us out. I’ll be down next weekend to take the left head off and hopefully take pictures of whatever is inside. I’d appreciate any ideas you all might have!
    #1
  2. kaput13

    kaput13 gasoholic

    Joined:
    Nov 20, 2010
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    668
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    South Florida
    Welcome to the forum tbg. Your experience is unfortunate but you have the right attitude. You are obviously going to learn a lot more than you might have bargained for. Sounds like you have already done some good research in looking for clues to what might have happened. Removing the left cylinder will be a good place to start but you can be pretty sure that based on your description of the oil filter that you won't find just :wink:a blown headgasket. Once you dive in and show some pictures or even before that you are going to get a lot of knowledgeable advice here. I'm working on my own 82 RS basketcase so I'm looking forward to following your thread.
    #2
  3. patrkbukly

    patrkbukly 52 Weeks of warm

    Joined:
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    Oddometer:
    1,671
    Location:
    Miami, FL.
    Hey TBG,
    I am a multi airhead owner including a 1980 RT. Maybe I know less, maybe I know more but either way we both own 1980 RT's so that makes it alllllright.

    Let us know how it comes out.

    Good news about the airhead is that as bad as it may be, between Ebay and ADV parts and know-how are affordable and in plenty supply so you will be on the road again soon and more confident with your knowledge.

    Post some pictures so we can drool.

    Watch posts from "Kaput"...we are in a gang together here in S. Florida and I am convinced he is someone famous in witness protection.

    WELCOME.
    #3
  4. disston

    disston ShadeTreeExpert

    Joined:
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    Location:
    Silver Spring, Md
    At first blush you have a completely worn out and wasted Airhead.

    We will have to see the cylinder head, disassembled, and the connecting rod bearings and the crank shaft, well lit photo please of condition of crank journal.

    The crank shaft is replaceable but they can be hard to find. Labor for putting a new crank shaft in will be about $500 (sorry that ones a guess really. A friend had this done two years ago but he never told me what it cost). The problem is the main bearings and thrust bearings. Tools for doing this are not the DIY type of tools.

    Same for the heads. Tools to fix them will cost more than what it costs to have it done. It will cost close to $500 to fix the heads.

    You are going to need the special socket to take the connecting rods out. This should cost you about $10.

    The valves come apart with a valve spring compressor. This will cost anywhere between $25 and $45.

    Engine oil is not "black" from burning up. It is black from mileage. There is one thing that never changes. You want to learn to be a mechanic then learn to change the engine oil. The oil is the life blood of the engine. The oil is cooling and lubricating the engine. Two things that are absolutely necessary for the engine to live. There is another side to life. It is death. When the oil gets old an engine wears rapidly. Too much wear and the engine dies. You were thinking maybe it was just a little tired?

    You may have been able to save this motor if you had changed the engine oil when you first got it but it sounds like the former owner didn't treat it any better than you did. The oil was already old. If not now this motor would have blown soon.

    Send pictures of the debris in the oil filter. Take the oil pan off. Send pictures of debris in oil pan.

    How's the transmission in this bike? Maybe you are in the market for another engine. Usually a much cheaper alternative to fixing something like you have described.

    edit; It's a good idea to fill in some info on your profile.
    #4
  5. Plaka

    Plaka Brevis illi vita est

    Joined:
    Jun 19, 2010
    Oddometer:
    4,625
    Get the VW book. Read it cover to cover.

    http://www.walmart.com/ip/1199599?w...1=g&wl2=&wl3=21486607510&wl4=&wl5=pla&veh=sem

    Or amazon, etc. No collectors editions.

    Get another bike to develop riding skills on. A small one with decent resale value.
    #5
  6. kaput13

    kaput13 gasoholic

    Joined:
    Nov 20, 2010
    Oddometer:
    668
    Location:
    South Florida
    Don't bail out on us tbg. Show us what you find.
    #6
  7. tbg

    tbg Bike Destroyer

    Joined:
    Jun 3, 2013
    Oddometer:
    18
    Location:
    South Dakota
    Thanks for replies guys!

    @Kaput - I appreciate the warm welcome. Looking forward to building along with you!
    @Patrick - What up 1980 RT buddy! Glad to hear most things are affordable.
    @disston - Thanks for the honest answer. Your price quotes are really helpful, and you're likely right, taking it to a dealer will probably be necessary. I'm going to try and get as far as I can without damaging anything. Would the dealer be upset if I brought the bike to them with one of the heads apart?
    @Plaka - Is there a lot of cross over from VW cars to BMW motorcycles? Or is the book itself useful for all mechanical applications?

    Alright, first off, I made a pretty stupid mistake: I live about an hour away from where I work on the bike, and forgot the manual when I came down to work on it. Whoops. Also, I was sans-bike-friend, and am no where nearly confident enough to take the pushrod assembly apart without the manual. That being said, I did remove the valve cover and got a look at the pushrods. Is it just me, or does the left pushrod arm seem a little bent outward? I linked to the album so I don't break your guys' tables: http://imgur.com/a/qdnls/embed

    I also managed to borrow a snake light and attempted to get a look at the piston head, but it was too far down the cylinder to differentiate anything apart. The valves seem intact though! I should be back down either Monday or Wednesday for a second go at it. I'll post pictures and keep you guys updated!

    Here she is in all her glory:
    [​IMG]
    #7
  8. Plaka

    Plaka Brevis illi vita est

    Joined:
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    Oddometer:
    4,625
    Rotate engine by turning rear wheel to bring piston to the top. At various piston positions, you can see the valves open and close and examine them as well.

    Lotta crossover with old air cooled VW. Both horozontal air cooled motors, the BMW a twin, the VW a four. Pushrod operated valve train. But the mechanical knowledge is the most important part. How to evaluate and tune things, exactly how it all works. Using different sorts of tools, making measurements, setting valves, etc. Different carbs and transmissions/drive lines. You'll see what doesn't apply, but as a basic course in working on these things that assumes you know nothing, priceless. Doesn't talk down to you, just doesn't miss anything.
    #8
  9. tbg

    tbg Bike Destroyer

    Joined:
    Jun 3, 2013
    Oddometer:
    18
    Location:
    South Dakota
    Wow, thanks for the really quick response. Unfortunately, I'm posting this from home, an hour away from the bike and snake light, but I'll definitely watch the engine rotate. Would I need it in 1st for that?

    I'll order the book after Tuesday. Payday!

    Also updated my info a bit. Midwest represent.
    #9
  10. disston

    disston ShadeTreeExpert

    Joined:
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    Silver Spring, Md
    To rotate the engine with the rear wheel. Raise bike on center stand, it looks like you have a Reynolds Ride Off Stand so you will have to put a piece of half inch plywood or other prop under the center stand to get the rear wheel off the ground. Once the rear wheel is not touching the ground put the bike in 5th gear and with the spark plugs removed you can rotate the engine.

    No more talking about taking bike to the dealer. That does not work. Dealers do not have mechanics that know or want to know about Airheads. Very few dealers have mechanics with any experience with Airheads. Their mechanics will merely be getting paid by you to learn the stuff you are trying to learn.

    You have both exhaust pipes off already? Try to take pictures as you go along and post them here. Here is the tutorial on posting pics on AdvRider. You will need an off site picture hosting service that can be linked directly to. Then the pics will have to stay there till not used anymore. Once you move or erase the images at the place where the pic is linked to here it will also disappear here.

    Nice looking bike.
    #10
  11. Plaka

    Plaka Brevis illi vita est

    Joined:
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    Oddometer:
    4,625
    4th or 5th.

    Book says turn engine w/ alternator bolt. Don't. It overtightens them. kickstarter good if you have one. jackstand under swingarm to hold wheel up helpful.
    #11
  12. disston

    disston ShadeTreeExpert

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  13. Kt-88

    Kt-88 I like everything.

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    Location:
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    Btw, that rocker isn't bent. It's just currently rocking. The pushrod is pushing out on that bottom end making the valve open.
    #13
  14. Warin

    Warin Retired

    Joined:
    Aug 30, 2012
    Oddometer:
    3,416
    On any secondhand vehicle you should

    change ALL the fluids (oil, water etc) and filters (air, oil). This gives you an idea of how things are.. if you find

    black oil - then I'd change it again after some small millage to give it a good flush.

    things in oil filters .. they come form somewhere .. best to find out now before the thing stops.

    ------------------------
    tbg while you are working on the motor .. I'd encourage you to drain and refill with fresh oil the gearbox, final drive and fork oils. Do look for black oils and metal particles ... report back on metal particles .. black oil = ride for a while .. say 500 miles or a month and change again. Oh - check the air filter .. a good shake should free any large bugs out. And take off each carb float bowel in turn and look for dirt and/or water in their bottoms.

    ================
    If you find lots of things wrong with the motor take a look at a bone yard - another second hand motor may be cheaper than new parts ...
    #14
  15. tbg

    tbg Bike Destroyer

    Joined:
    Jun 3, 2013
    Oddometer:
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    Location:
    South Dakota
    Got the engine and piston head off/out of the bike. The piston rod is... almost floating? I'd say it's got a lot of play. I think the bearing might have come off/been destroyed. The piston has a chunk of the top gouged out, which apparently took the top of the engine block that sealed the piston, and a chunk of the cylinder head off with it. I'll post pictures tomorrow.
    #15
  16. kaput13

    kaput13 gasoholic

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    Location:
    South Florida
    The good news is that is still a nice looking bike :D. Should be interesting to see your pics of the damage. If the desire is there, everything can be repaired or replaced.
    #16
  17. disston

    disston ShadeTreeExpert

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    tbg,

    You now have a blown engine. It is entirely possible that this can be fixed but we will have to see some pictures of the damage to tell. At first blush I'd say this one is toast. Would be much more expensive to fix instead of finding another engine to put in this bike.

    You mention engine block damage and cylinder head damage and a bad bearing. The bearing may have damaged the crank, the cylinder heads are almost always lost if broken pieces are hitting them, and the broken place between the block and the cylinder is not even repairable. Just from your descriptions understand so please post some photos.

    We will help you find another engine.
    #17
  18. tbg

    tbg Bike Destroyer

    Joined:
    Jun 3, 2013
    Oddometer:
    18
    Location:
    South Dakota
    Progress!

    @Kt-88 - Awesome. Good news for a change!
    @Warin - Absolutely. Doing the oil filter change was pretty exhilarating, can't wait for some more basic maintenance. :evil
    @kaput - Exactly my hopes!
    @disston - I wish I could say you're wrong:

    Sans-Clymer, I had unscrewed the very obvious parts connecting the cylinder head to the engine, but missed some crucial bits. With the manual in hand, I began to remove the carb, as per instructions:
    [​IMG]

    It took me longer than I'd like to admit before I unscrewed the gunky-throttle-and-clutch cables:
    [​IMG]
    [​IMG]

    Like some unholy god, she gazed back:
    [​IMG]

    The valves, pretty damn dirty:
    [​IMG]

    Leading to the bad news. NSFW:
    [​IMG]
    [​IMG]
    Taken from a low angle, camera tilted counter-clockwise. Damage matches the cylinder head and piston head:
    [​IMG]

    Missing a lung:
    [​IMG]

    In addition to the damage on the top of the cylinder assembly, the piston can be wiggled on all up/down/out/in. Shouldn't that be firmly locked to the crankshaft? Maybe the main bearing went, freeing the piston to tear the cylinder out?

    I'm in for the long haul with this bike, so give it to me straight. I appreciate your support!
    #18
  19. Kt-88

    Kt-88 I like everything.

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    SLC area, Utah
    Disston is totally on point here.
    #19
  20. disston

    disston ShadeTreeExpert

    Joined:
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    Oddometer:
    12,368
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    Silver Spring, Md
    I don't see any damage to the head. Is there something I'm missing? The fact that the valves and the rest of the inside of the head is coated with oily carbon just means this engine has been running in a completely worn out condition for a long time. Unless there is something there that I haven't noticed the heads are now good project parts. They should be examined further by somebody, possibly the mechanic that will rebuild them.

    I don't see any problems with the carburetor. This amount of blow by gases on the carbs is not even really bad. Looks like maybe they were cleaned sometime before you got the bike.

    Put these parts on a shelf. Put the valve covers on the heads to help protect them. Be careful if you pack stuff in boxes that you don't break any of the fins on the heads or cylinders. Be careful with the rockers. Keep them on the short shafts because they have needle bearings in the rockers and you don't want to loose any of the small needles.

    You can store stuff at this point in it's dirty condition. Stuff will get cleaned later if it is being reused.

    I see the one spot on the piston that looks like it hit the cylinder skirt. Is there metal flakes on the cylinder skirt from the damage or is that just dirt? You should not be making stuff dirtier as you take it apart. Keep dirt out of the engine parts, even the parts that are no good. The cylinder is trash and the piston also. But don't throw any of the parts away, not yet. You don't get to throw the broken parts away until the bike is up and running again.

    I do not see any damage to the engine block? Please point out anything I am missing and post another picture if you can of damage we are missing.

    Your next step is to take the piston off the rod and take the rod off the crankshaft. This operation is explained in the manual. Ask about anything that's unclear. You will need at least the triple square socket for the rod bolts. I don't know if the wrist pins in a 1980 are wires or circlips. If they are wires they come out by prying one end out. If circlips you will need a good set of circlip pliers. Let us know what you have for tools and we'll suggest what will work.

    Tools are going to be your new passion. It may seem that you are not getting enough use from some of this stuff but you have to get your own tools and you will use most of it again and again, eventually.

    Use this place to buy special tools you need. At this point the fluted socket for the rod bolts is I think all. You may find this socket cheaper at some places like Sears and the Craftsman tool is strong enough but there is a thing about these special tools that you will appreciate more someday. The tools you need for this work are not the cheaper variety. This particular socket does come in a cheap version that breaks. So get the one from Cycle Works

    http://www.cycleworks.net/index.php?main_page=product_info&cPath=29_33_51&products_id=27
    #20