| Author | Message | ||
     Hughlysses |
Listen for yourself: I removed the primary cover earlier today and checked the primary nut. I couldn't get it to budge with a 1/2" breaker bar so I'm pretty sure it's tight. Primary chain is adjusted correctly. Noise seemed to start yesterday and get worse as the day went on, over a ride of about 1000 miles. Oil level is fine (Mobil-1 20W-50 since ~5500 miles) and I've changed it at ~2500-4000 mile intervals. I've taken good care of this thing; I can't say that I've ever even hit the rev limiter with the thing. The bike has about 29,000 miles on it. Can any of you suggest something it could be other than a terminal bottom end problem? I am REALLY bummed right now... | ||
| Rwcfrank |
The only thing I can recommend is to pull a plug wire on each cylinder one at a time. With no spark there is no load and this will tell you if the crank / con rod and which one is shot. Good news is if that makes no difference your crank may be okay. | ||
| Teeps |
Sounds a lot like an exhaust leak to me. Any ugly vibrations to go with the sound? | ||
| Hughlysses |
It's definitely not an exhaust leak; it sounds very "metal-on-metal" in real life. No noticeable increase in vibrations. | ||
| Uly_man |
I am no expert on these engines and given that you cant tell much from the vid but it sounds like cam shaft/rod wear. Which is expensive to repair and/or near terminal. Hard to say though. The thing to do is start with the basic tests. Oil pressure, head compression and work form there on. You may have just a worn oil pump. Who knows. Good luck Sir. | ||
| Uly_man |
I had an exhaust leak and it did not sound like that at all. | ||
| Xdigitalx |
I am no expert either but sounds like it is running on one cylinder... laptop speakers... | ||
| Hughlysses |
As I listen to the video again I'll swear it sounds louder on the left side of the engine than the right, as if it IS the primary sprocket. OTOH I tried the trick of putting it in gear and easing out on the clutch and it made no difference in the noise at all. I put a good ~100 ft-lbs of torque on that breaker bar and the crank nut would not tighten at all, so I can't see how that nut could be loose. | ||
| Road_thing |
Could be loose magnets coming off the alternator rotor. rt | ||
| Panhead_dan |
Hughlysses, Its all part of being a life support system for a motorcycle. I know you are really bummed out right now as I would be but try to relax. First, don't run it any more. The bike is a machine. Nuts and bolts. We can outsmart it. You need to isolate the problem obviously but without running it much right now so set it up with an oil pressure guage, drain the primary/trans and remove the outer primary cover. Get your hands on a leak down test setup and a mechanics stethescope. The next time you start it, be ready to test and listen to everything you can. (Leakdown test is done with the starter only) Others with more knowledge will hopefully post some more ways of finding this problem before you try to start it again. If it fails no tests, what ever remains is broken. I'm hoping it something cheap and easy. | ||
| Reepicheep |
Ugh. That doesn't sound good.  After checking primary / magnets, you can get the cam cover off also, which also lets you check the rocker boxes. So that lets you check everything and you are still only maybe 8 hours of labor into it. Sorry Hugh, bummer. | ||
| Wesman |
Sigh..... the bike looks bone stock, no high performance mods, Can someone Anonymously help out? | ||
| Hughlysses |
Thanks for the words of encouragement guys. Dan, yep, it's just nuts and bolts, and I've got the books on how it's put together. I'm pretty confident of my ability to deal with anything that's not in the bottom end; if it's that I'll either find a used engine or part it out and buy another Uly. I'll probably leave it alone for a week or so and then start tearing into it gradually. I've got another bike I can ride (1983 Honda VT500FT Ascot) so I can stay sane in the meantime. Wesman- Yep, it's bone stock as far as the powertrain goes. It's pretty disappointing to have the engine go south with less than 30,000 miles on it. | ||
| Charlie_zulu |
Cam bearings..? | ||
| Tootal |
Hugh, sorry to hear that video! It sounds like rod knock but being roller bearings I can't see that being the case. I have dealt with two friends bikes, (Harley's), that made nasty noises like that and they both were bad cam followers. When I pulled them apart the cam had ate into one of the rollers on a tappet.  They must be case hardened and sometimes the depth of hardness is not enough and once it breaks through to the soft stuff underneath it just wears like crazy. Your lifter/tappet will make up the difference in wear for a while but it runs out eventually and you get nasty noises. I hope it's easy to get to whatever it is!! | ||
| Hughlysses |
Tootal- Thanks for the suggestion. A lifter and a cam would be a big job but at least within my abilities to fix. I sure wish there were some way to do a visual without rotating the engine out of the frame. Do you think a compression check would help diagnose this? I.E.- if one valve isn't lifting (or not lifting much), the pressure in that cylinder might be much lower than in the other. (Message edited by Hughlysses on February 21, 2011) | ||
| Tootal |
Yes, it should make a difference and I would recommend that anyway, always a good tool. Just remember to put your plug back in the wire and ground it or just unplug the coil. Also remember to open the throttle all the way when testing. I've been doing this crap for years and I still make that mistake. I realize it as soon as I see the numbers!! Well I was thinking you might be able to look at the cams without rotating the engine but I just went and took a look and the exhaust is in the way and I think you have to rotate it to get the rear exhaust off. Crap! The more I think about it, the compression check might not show a huge difference. You still are opening the valve and at the slow rpm you will be cranking the engine at you will still have time to fill the cylinder and get a good reading. I would do it anyway and if they are within reason of being the same I still wouldn't rule this issue out. I was looking at the push rod covers. Unfortunately you can't just pop them open like a Harley and check to see if one is loose. Seems like it might be time to enlist in Dr. Greg's engine rotation dynamics 101 class!!  (Message edited by tootal on February 21, 2011) | ||
| Buellhusker |
That almost sounds like a collapsed piston. | ||
| 7873jake |
Usually, on old Triumphs I'm working on or have been riding, when sounds like that show up, a quick drain of the oil pan reveals shiny bits, slivers and/or shards in the drain pan. Granted, the two bikes couldn't be more dissimilar (I offer that as, uhmmm, comfort?) but its worth a peek... | ||
| Towpro |
The knock frequency does sound 1/2 the speed of the Motor. Which is the same speed your came turns at. But I'm not expert to diagnose by listening to a video over my laptop. | ||
| Hughlysses |
Towpro- It does sound like that. Lord knows I'd much prefer failure in the valve train to failure in the crankcase. Like Tootal said, I guess Doc's class in Engine Rotation Dynamics 101 is next on the agenda. | ||
| Gunut75 |
I took Doc's class. It is the best around. Rotating the motor down is easy. The XB in my opinion is about as complicated as a riding lawn mower. Probably why I like em so much! If you have your service manual handy, you will be fine. Good luck! | ||
| Xoptimizedrsx |
collapsed Lifter 95% sure. start it and use a stethoscope or wooden stick to listen to it. It will clank loud at the bottom and top. more tinny at top than bottom. Lifter are ls1 chevy rollers one box will do 4 bikes. get anti pump up style. while apart replace springs on the valves and check the rocker arm bushings for up down movement. total parts and upper gaskets for rocker box about 120.00 out the door. Thats if you use the chevy lifters or stock. dont get fuelings they are JUNK... comp cams lifter promagnums are low cost and good. but like I stated they are chevy Lifters. lol Tested and true. xl cams also fit fine in the bike to set key way cut new notch in align with the center ^ mark. thats the correct key location for the rotor cup. Install as normal done saved you 200 plus on cams as well. Instructions with pics are on my website for free on cam setup. have a great day folks... Xopti | ||
| Xoptimizedrsx |
http://xoptiinside.com/yahoo_site_admin/assets/doc s/XL_cams_in_XB.25133855.zip The Link to the Xl setup in an xb. | ||
| Hughlysses |
Xopti- thanks VERY much for the response. It gives me some hope I won't have to tear into the bottom end. I'll do detailed check on source of noise as you suggest. | ||
| Jlnance |
Hugh, make sure Pammy sees this thread. | ||
| Hughlysses |
Jim- thanks for the excellent suggestion. I just sent her a PM. | ||
| Pammy |
It sounds like a connecting rod or wrist pin. Sorry dude. There should be metal with that. Drain oil and drag a magnet through it. Or put it in a clean container and look at it in the sunlight. Let us know the results. | ||
| Midnight_rider |
i was guessing wrist pin also only way i know is to take her apart | ||
| Hughlysses |
I e-mailed the Buell tech at my dealer (Jadow) and he apparently responded, but it the wrong thread. Here's what he had to say about it: "This is a tuff one. With your description of RPM, and the suggestion of Lifter, with no oil flowing out the exhaust No damage to the spark plug (Piston seems together) It is not uncommon for the rear exhaust valve to seize. The compression test will not show completely because the valve rest with spring pressure, but run it and the seized middle of the guide allows the rocker to hang behind. Piston to valve clearance can be stressed so I wouldn't run it much more at the RPM range that produces the noise. At this point try everyone's testing suggestions, rotate remove rear head, take spring off push valve..it bet it won't move : (Easy fix and back on the road." That's interesting about the rear exhaust valve occasionally seizing; hadn't heard that one before. Whatever it is, time to get the wrenches out and start looking further. Thanks to all who offered suggestions and/or sympathy. I'll report back as soon as I find something. |
