| Author | Message | ||
     Andrejs2112 |
I have been troubleshooting a nagging vibe in my Uly for a while. I changed the front isolator, no luck. I've checked to see if the muffler fasteners were loose. Not a problem. The muffler actuator works fine too. Does anyone know the feeling when you are riding two-up and go over a dip in the road? On the way down the bike feels like it is rubbing, or gets a weird pulsing when the shock is compressed. That's what's happening when around 4000 rpm on my bike. Under 4k it smooths out. It's driving me nuts! Any ideas? The only major change I've made was changing the primary to a "9" last winter. Could something be loose in there? I don't hear any funny noises coming from there. Thanks, ar | ||
| Jb2607 |
I experienced the same situation on my latest cross country venture. At speed with weight on bike when I bottomed out in dips in the road, I felt a soft shudder... It never caused a problem and I thought it may be belt tension. Good question. | ||
| Seanp |
I felt that rubbing feeling too, riding two-up with loaded bags. I just figured it was just a little too much weight on the bike, and it was protesting. It went away once I lightened the load. | ||
| Etennuly |
I believe what Andrejs2112 is saying, is that he is feeling that same rumble/vibe at 4000 rpm when he is NOT in a dip, as in all of the time at that rpm. Is this correct Andre? Is it possible to have the timing off between cylinders? Perhaps a bad plug wire or coil? A plugged or failing injector? Sounds like one cylinder is giving up at that speed. Have you inspected the plugs? | ||
| Conchop |
I've been up to my eyes with vibes. Look at your isolator and you will see 2 wings and a strip. The wings suspend the motor and the strip is a backstop. When you hit a bump or dip, it stretches the front and rear isolators until it hits the strip [ backstop ]. This connects the motor to the frame and then its 1969 XLCH Sporster time. When I put the momma on back, I'm afraid we have just a little too much weight and the rear shocks sag and we catch a buzz. Funny; my Victory's never had that problem. Of course, they were counter balanced. There are primary and secondary vibes with big v twins without the counter balancers. We're dealing with 1952 technology here. Instead of making a modern motor, we get to deal with super refined old technology suspended in rubber. The cure for my vibes were a set of irridium plugs that were properly torqued down [ unlike the ones the factory trained mechanic installed ]. You can also: 1. Fill the handlebars with silicon 2/ Put on some HVMP handlebar weights 3> Use synthetic oils. 4? Check your primary chain adjustment. 5/ Fill up with Aviation gas or hi-octane racing gas. 6. Lubricate the Heim joints with silicon spray. 7. Tighten the muffler. 8. Make sure the horn is not hitting the cowl. Piece of rubber tubing wedged behind it keeps it from rattling your head. 10. Tighten everything else. 11. Propery adjust your suspension. 12. Buy a Gold Wing! lololol | ||
| Andrejs2112 |
Etennuly, Yes I mean that my bike is vibrating on flat ground not under a load. I did change out my plugs and wires recently. My bike seems to run fine, it just vibrates. I'll check the plugs and wires. The vibes feel as though they are coming from the engine...not a loose horn. I checked that too BTW. | ||
| Andrejs2112 |
Conchop, Did your plugs loosen up on you? What kind of vibration did the loose plugs result in? | ||
| Pso |
I also have noticed that mine has a strange vague rubbing type feeling at close to 4K also. It is on smooth pavement and does not seem to be load related, nor speed related but more sensative to RPM. I am not sure what it is. I just changed out my plugs so I will re-torque them and see if that makes a difference. Also I am due for a new rear tire soon so I will also check the rear bearings. This sort of reminds me of when one of my front bearings went out on my IH Scout. | ||
| Ikeman |
I don't get the vibration just steady-state, flat road running like Andrejs2112 is talking about. But, it didn't take too long to figure out where the vibration was coming from when the suspension compresses (especially while 2-up). Take off the seat and look at the valve cover on the rear cylinder. Is there a worn spot on it? That's where the vibration is coming from - seat-to-valve cover contact. So, maybe after the plug change the seat is just situated a little differently and it's making contact more consistently. My 2 pennies... | ||
| Andrejs2112 |
I'll check it out. I'll kiss you if that is the problem. Just kidding about the kiss. | ||
| Andrejs2112 |
Yes, There seems to be at least 3 seat to frame contact points and one valve cover to seat contact. I'll investigate a way to shim up the seat and see if I can eliminate the contact points. It makes sense that it would be an issue. I'll keep you posted... | ||
| Ikeman |
I'll forgo the kiss, thanks anyway... A bit more clarification - when I get that vibration it almost feels like the tire or belt is rubbing on something when the suspension compresses and then goes away when it unloads. I twiddled with the suspension quite a bit and the only variable that really made a difference was the amount of weight on the seat. | ||
| Andrejs2112 |
That's exactly what I'm feeling. It's hard to explain, but your description works. I am sort of a fat ass at 250. I wonder if the rest of us "big boned" fellows are having similar issues. It makes sense with a passenger because when that much weight gets compressed onto the seat, the seat would contact the frame more. I really hope that is the problem. Thanks for the input. | ||
| Seanp |
I'll check mine out tomorrow, but I think I'm getting the same thing. Maybe this thread will help us all out: http://www.badweatherbikers.com/buell/messages/406 2/325600.html?1217277966  | ||
| Andrejs2112 |
I looked at mine closer tonight. There is only one place that the seat touches the engine. I couldn't figure out a way to shim up the seat so it didn't touch so I cut out the part of the seat plastic that was touching. I'll test it out in the am. | ||
| Jameslaugesen |
I think I am noticing this same vibration when the suspension is compressed; riding through a dip, leaning hard through a fast corner on the track, etc. Feels sort of like the belt is too tight. I had guessed it could be something in the drive line; idler pulley bearing, drive pulley, something like that. The theories here make more sense though I think. I'll look for seat to valve cover rubbing marks tonight. But I'm only ~75kg, very rarely two-up, and I usually stand on the pegs over bumps and when cornering fast... so I _think_ I am feeling the vibration through the pegs. Will check that next time I ride, haven't paid much attention in the past. Ikeman, so your suspension changes made no difference to the vibration? That's that test I'm planning, firmest suspension vs soften suspension, front and rear... that would at least eliminate my belt/pulley/bearing worries. | ||
| Baydog |
I've experienced the same "shudder" as the suspension compresses in dips, etc. It feels and sounds to me like a belt tension change. I don't notice any difference as far as engine rpm or road speed. It is strictly suspension load related. When the suspension compresses you can feel it. The softer the suspension is set, the worse it gets. Cranking up the compression damping makes a big difference in minimizing it. It may be my imagination, but I think changing the front isolator helped a bit too. That part definitely helped in overall vibration reduction. I would love to pull the rear shock off and check belt tension throughout the suspension travel. I suspect this would tell us a great deal about what is going on. Unfortunately I don't have a belt tension measuring device. | ||
| Desmo900 |
Maybe use a fish scale. | ||
| Seanp |
Wow, so I guess this is the rubbing that I'm feeling under a load, taken this morning with my cell phone: http://gallery.me.com/sean.mccafferty/100016/photo 1217337831897/web.jpg http://gallery.me.com/sean.mccafferty/100016/photo 1217337869137/web.jpg http://gallery.me.com/sean.mccafferty/100016/photo 1217337937359/web.jpg | ||
| Conchop |
Andrejs2112 To answer your question about the loose plugs - They were not properly torqued down to begin with. The crush rings were far from being crushed. When I went to unscrew them, there was no initial "stick" that is usually associated with unscrewing a spark plug. I'm not sure, but there appeared to be some blowback carbon around the thread. My vibration was a horrible buzz around 2500 to 3000 rpm. The bike was buzzy in general. Every ride I took numbed my hands. There are still vibrations as there will be with any v twin. However, my hands have yet to go numb since I installed the irridium plugs and torqued them down. I took my wife for a spin and the weight put the backstop on the front isolator right up against the the wall of the isolator. Buzzed like hell. My current vibes are at 2500 to 3000 [medium high] - 3500 [light] 4100 really light - there are some at the upper ranges but I can't tell exactly where because things are happening faster than I can look at the tach! Like I said, my hands are not going numb now, but vibes are vibes and they are a nuisance. PS - Make sure your ecm isn't rubbing the bottom of your seat. I filed mine down a little but I think a hole drilled in the seat bottom is a good way to isolate it is a good technique also. | ||
| Red_chili |
So it sounds like a seat lift might be in order. Another terrible awful how-could-they-do-that Buell issue fixed for $.49. OK, mebbe a buck two fiddy.  | ||
| Ikeman |
Jameslaugesen - For the most part, suspension changes didn't do much. I will say that I remember very soft was slightly worse than very stiff. And I believe the reason for that was the bottoming of the suspension on soft settings. A short, sharp bump won't cause the vibration, or at least the duration isn't long enough to feel it. I can't remember having it happen while cornering unless there was a dip in the middle of the corner. You basically need a situation where you are pushed down onto the seat relatively quickly and remain there as the suspension starts to rebound - a nice dip in the road. Seanp - Yep - exact same spot. It hasn't gotten any worse on mine so I don't even worry about it. By the way, I did check the belt, pulleys, rear fender, tire, etc. - everything I could think of looking for some sign of contact. Nothing other than the seat and valve cover. And like I said, the only thing that significantly changes the occurrence of the vibration is the amount of weight on the seat. The Uly vibrates in all kinds of different ways (how about 80mph with bags and without?) but this was the only one that made me really feel like I needed to investigate. YMMV and all that... | ||
| Andrejs2112 |
Well, I cut out the seat pan area that was rubbing on the valve cover and my mystery vibe is gone. I would have never guessed it, I would have spent hours taking things apart. Thanks Ikeman, and the rest of you guys for the info. It's much appreciated. | ||
| Ikeman |
 Glad that's all it was. | ||
| Etennuly |
I have two spacer blocks on either side of the ECM. I checked my seat for rubbing on the head and have no marks. I am installing a new belt this weekend and have been thinking about that spring belt tensioner. Hmmmm??!!  | ||
| Longdog_cymru |
Funny, (or not), I just got back from my first long trip to Ireland with SWMBO and many of the smaller back roads are atrocious. I noticed that when we were going along roads with large dips that caused the suspension to load up, there was sort of vibration or rubbing sensation, which I thought may be from the belt. I don't really have an explanation and it didn't appear to be rev related as described by some on this thread, but I am sure it was the same thing. For the record, I weigh in at 190lbs and SWMBO comes in at 125lbs and I had wound on 16 - 18 turns of pre-load on the rear shock | ||
| Andrejs2112 |
Etennuly, Would you happen to have a photo of those spacer blocks to clear the ECM? |
