| Author | Message | ||
     Reepicheep |
Dang. Was warming up the Uly in the driveway and heard a "tink tink tink tink" noise. I've learned over the years to take "tink" noises *very* seriously. Sure enough, after some hunting, I find what is clearly one corner of a Buell head.  It sheared half way across the bolt mating surface, all the way down. I'll post pictures later. I had the airbox plate off after the crash and checked the front head, and didn't see it there, so it must have been the back head. I have new plugs on the bench and was going to rotate the motor and inspect for damage this winter anyway... I guess now I know. So now I have to decide if I should try and repair this head, source a used one, or get a new one. Pammy? Any opinion? Also, I have been lead to believe that if you pull off the head, you need to pull the cylinder and replace the gaskets anyway. Is that correct? Or is it just if you break the base gasket seal? | ||
| Reepicheep |
  I'd love to find out this was the rocker box or something, but I'm guessing its the head... | ||
| Rr_eater |
I have seen the head pulled and replaced without base gasket replacement, but it's a chancy ordeal, wiggle the cylinder while it is not clamped down, and leaky leaky. Until you get the head off, there is really no telling how extensive the damage is internally. I would plan on at least a used head, tons available on ebay from tear-downs lately. Freshen it up and go with it, or pull them both and get some port/polish work done while they are off, just a thought. But before anything, get it off and make sure it is the head, or are we talking about the rocker box? With the engine rotated, a gasket set, and good tools this is not an impossible or ungodly job, just sucks. But if you crashed hard enough to crack a head, I am glad to hear you are OK after it all!! Bruce | ||
| Reepicheep |
Cracked pelvis, and cracked molar. ATGATT... I was on a quick "errand" 5 minutes from work, but was wearing armored pants, armored jacket, armored gloves, armored boots, and a spine protector (which was under the spine protector in the jacket). Even my armor has armor.  I've done the engine rotation before, no big deal at all. And I've done rocker boxes on the M2, this will be easier, as I won't weld a spanner to the battery this time (DAMHIK). Gotta finish cleaning the garage before I tear into it, and I have a dirt bike to rebuild for the kid. I better get busy... | ||
| Billyo |
I saw the same thing on my front head after my son wrecked my firebolt. After finally getting it back together and riding it a few times, I was looking it over again and just happened to see, behind the left side scoop, the bolt from the front isolator where a piece just like yours had broken off. I'm planning on trying to replace the head this winter (funds permitting), but in the mean time, I experimented with layers of JB Weld built up in place of the missing piece. I've ridden it conservatively several times since my redneck repair and have been surprised that it hasen't broken again. I know it's just borrowed time and I need to fix it right soon. Good thing I ride the uly most of the time anyway. What really surprised me too, is that before I saw the damage there was no vibration or any other sign that anything was wrong. | ||
| Reepicheep |
Mine has has several thousand miles since the accident, running with no problems. That piece just finally worked its way free. At some point, I'm guessing those unsupported threads will "jump" or break, and I'll have a head gasket leak. Which on an air cooled motorcycle, may be just about indistinguishable from not having a head gasket leak. I wonder how far down those threads go... Maybe it really doesn't matter... if there is another inch of threads below there, that effectively just ends up being a spacer, and maybe JB Weld would keep it there. | ||
| Dr_greg |
Whew! From the subject I thought it was YOUR head that was broken...  --Doc | ||
| Reepicheep |
Had a Schuberth Concept C1 to prevent that! Looking at the helmet, I didn't think it was that bad a hit. But the root canal I got 20 days later suggested that maybe it was a little worse than I thought (molar probably cracked during accident, took about a month for the root to get infected). For the record, a cracked molar with an infected root hurts worse than a cracked pelvis, if anyone cares. And a cracked pelvis ***really*** hurts. | ||
| Mnrider |
 I guess I was lucky mine just broke the bolt on the left engine support frame and bent the one on the right after my crash. I heard a squeek noise when pushing the bike into the garage.  | ||
| Billyo |
  Maybe I'll just do an experiment and see how long it will last. | ||
| Reepicheep |
Thanks for the pictures. Mine sheared that bolt as well. I inspected the head visually (did not pull the rocker box) at the time I repaired it, but did not see a crack. Time will tell when I rotate the engine. I have a new dirt bike for the 11 year old to rebuild, and his old dirt bike started making some not happy noises that will have to be addressed before I can sell it. Lots to do this winter... | ||
| Reepicheep |
The Queen has spoken! Repair is always possible, but not necessarily worth the trouble relative to just getting an intact head. So I'll start stalking ebay. So will any XB12 head fit a 2007 Uly? Heck, for that matter, are the 9 heads the same? | ||
| Mark_weiss |
Why not take the head to a good welding/machine shop? That type of damage is pretty easily welded up and re-machined. Should cost a lot less than a new head. | ||
| Reepicheep |
Dang... I smell a delimma coming. Thinking about that head today... while... uh... riding the bike on I-75... it occurred to me that since that part is tapped, it *can't* be the part of the head that holds the head to the motor. And because the tapped hole is perpendicular to the cooling vanes, it must be holding the rocker box to the head, not the head to the bike... So now you see where this is going... How deep does that bolt actually go into that head? Two vanes worth are cracked off now. But the bolt only needs about two bolt widths of good threads to have full strength. So if that bolt is long enough, and the threads deep enough in the head, it still may be 100% strong. Anyone remember how deep that rocker box to head mounting bolt sits? Looks like I have lost a little under an inch, and need a little under an inch (2x bolt width). Is it a 2" or more bolt? | ||
| Garrcano |
Uly2006 Parts book: Item5 page 8, part number 4718A,Bolt 1/4-20 X 1-1/2 hex socket hd sems zinc. | ||
| Reepicheep |
Thanks! My parts book is at home, and I am at work. Hmmm. That doesn't look like a 1/4 bolt. Closer to 1/2. I should just stop thinking about it until I go home and take it apart and see what is really chunked out. | ||
| Hughlysses |
Bill, it sure seems like it'll be OK as-is. Worst that can happen is it will eventually start to pull out and the rocker gasket will start leaking. | ||
| Reepicheep |
Well then... that's good and truly knackered... Had some good help from the oldest..  To get this part out  Revealing a trashed head  Time to email Pammy and see if it is worth repairing given you can get a replacement head for like $300-$400 (cheaper than for my KLR-250 thank you very much). | ||
| Reepicheep |
Ugh. Finished pulling more apart, the other end of that brace had almost the same crack. That bracket was about to fall off completely. Yikes. That would have left the rear of the motor unsupported. The hole was ovaled as well, meaning the thing has been beating around for a bit. I'm smelling a new head in my future... :/ | ||
| Natexlh1000 |
Perhaps it would be prudent to investigate the rest of the engine mounting points. | ||
| Reepicheep |
One of the front V bracket bolts was sheared, I found that doing the original repairs. Now that I have it *really* apart, I checked close, and see nothing else. I'm not sure how that much aluminum can shear and not damage the frame (which had the other end of that load), but it was fine. | ||
| Reepicheep |
OK, got the head off. It's pretty knackered, so I'll just hunt a replacement. Have some queries out now, but if anyone has a 20k mile Uly 2007 rear head, I'm all ears. How does this piston look? Nasty on one hand, but on the other hand that's 20k miles, and its (aside from being crusty) in great shape.  | ||
| Reepicheep |
Given that I'm pretty sure I should just get a new head anyway, I may try welding on this one just for fun with my Oxy Act rig (which I have special flux for). Just to see how hard it is to do well. | ||
| Blake |
Crusty! "Just to see how hard it is to do well." heheheh Sounds like fun, at least at first. Will look forward to the photo documentary. | ||
| Mark_weiss |
That is not the type of damage that you repair by welding the broken off bit back to the main casting. A broken screw hole is best repaired by using welding beads to build the area back up sufficiently to accommodate re-machining. I don't know that I would try that with gas welding. TIG is much better suited and will yield a fully usable part. | ||
| Reepicheep |
I'll definitely source a replacement before I do anything permanent to this one. I don't doubt it could be repaired, but that was a hack of an impact, and it looks like a new head will be $300 or less. So cost wise, new or repaired will probably be a wash. I wasn't going to try and weld the old pieces, I was going to build up the whole area and drill and tap the holes again. I don't have any TIG, and no gas or aluminum gun for the MIG unit I borrowed, so Oxy Act is my only choice. I should probably just put it in bubble wrap as is and put it on a shelf... | ||
| 7873jake |
offerings to the god of speed | ||
| Reepicheep |
So that piston is reasonably normal for 20k miles on a stock XB12? The "gunk" is crustier than I expected... I expected it to be about that dirty, but a flat layer of carbon. | ||
| Dynosaur |
What does the skirt look like? | ||
| 7873jake |
The top doesn't look horrific in terms of the build up you see. I can't speak to the color and have to assume that the lighter 'color palette' has to do with a much more precise (more lean?) air/fuel mixture being burned in the combustion chamber than that of most carb'd bikes I've looked in to. Most, if not all, were darker than that. Not to over-simplify this but does your plug tip(s) match the color of the piston? Just a curiosity. Like Dynosaur, I'd be interested in the state of your skirts. All sorts of things and the way they are burned can account for colors in the combustion chamber but I like to see the wear patterns in skirts too. | ||
| Reepicheep |
Skirts and cylinders look brand new... tips of the spark plugs are perfect tan colored. I've become a head hunter... | ||
| 7873jake |
It sounds like the tips of your spark plugs matches the burn color on your piston. Unless someone here has specific knowledge that your crown shows evidence of some oddity, it doesn't raise any real concern just by the way it looks in the picture. Happy hunting! |
